Irving   Stringham 


m 


THE  AMERICAN  SCIENCE  SERIES. 

BRIEFER    COURSE, 


ASTRONOMY.  By  SIMON  NEWCOMB,  Supt.  Ameri 
can  Nautical  Almanac,  and  EDWARD  S.  HOLDEN, 
Director  of  the  Washburn  Observatory.  $1.40. 

THE  HUMAN  BODY.  By  H.  NEWELL  MARTIN, 
Professor  in  the  Johns  Hopkins  University.  $1.50. 

ZOOLOGY.  By  A.  S.  PACKARD.  JR.,  Professor  of 
Zoology  and  Geology  in  Brown  University,  Editor 
of  the  American  Naturalist.  $1.40. 

POLITICAL  ECONOMY.  By  FRANCIS  A.  WALKER, 
President  Massachusetts  Institute  of  Technology. 
$1.50. 

BOTANY.  By  C.  E.  BESSEV,  Professor  in  the  Iowa 
Agricultural  College  and  late  Lecturer  in  the  Uni- 
versity of  California.  $1.35. 


HENRY   HOLT    &   CO.,    Publishers, 

NEW   YORK. 


AMERICAN  SCIENCE  SERIES,  ELEMENTARY  COURSE 

THE  HUMAN  BODY 

A  BEGINNER'S  TEXT-BOOK 

OP 
ANATOMY,  PHYSIOLOGY  AND  HYGIENE 


WITH  DIRECTIONS  FOR  ILLUSTRATING  IMPORTANT  FACTS 

OF    MAN'S   ANATOMY    FROM   THAT    OF   THE    LOWER 

ANIMALS,  AND   WITH  SPECIAL   REFERENCES  TO 

THE  EFFECTS   OF  ALCOHOLIC  AND  OTHER 

STIMULANTS,    AND    OF   NARCOTICS 

BY 

H.  NEWELL  MARTIN,  D.Sc.,  M.A.,  M.D.,  F.R.S. 

Professor  of  Biology  in  tlie  Jolins  Hopkins  University 

AND 

HETTY  GARY  MARTIN 


NEW   EDITION   REVISED 


NEW  YORK 
HENRY  HOLT  AND   COMPANY 

1885 


UM 


G 


COPYRIGHT,  1884, 

BY 
HENRY  HOLT  &  CO. 


\ 

A 

A 


V\      V£WY\  6  ?v     ciYY\ 
Y  \J\Y\ 


-J5 


PREFACE. 


THIS  little  book  is  an  attempt  to  express  accurately 
and  yet  in  simple  language,  those  facts  concerning  the 
structure  and  actions  of  the  living  human  body  which 
it  is  desirable,  for  practical  purposes,  that  every  one 
should  know.  It  is  essentially  a  school-book  of  personal 
hygiene.  Little,  if  any,  more  Anatomy  and  Physiology 
is  introduced  than  is  necessary  to  make  clear  the  reasons, 
as  regards  the  preservation  of  health,  for  following  or 
avoiding  certain  courses  of  conduct.  This,  of  course, 
includes  all  the  broad  facts  of  Human  Anatomy  and 
Physiology;  but  subjects  of  merely  professional  impor- 
tance or  of  purely  scientific  interest  have  been  omitted. 
As  regards  Hygiene,  attention  is  for  the  most  part  only 
directed  to  matters  which  are  usually  within  the  easy 
control  of  each  individual.  It  seems  useless  to  burden 
boys  and  girls  with  sanitary  laws  which  need  the  aid  of 
a  physician  or  engineer  for  their  successful  application. 

A  very  earnest  attempt  has  been  made  to  present  the 
subject  so  that  children  may  easily  understand  it,  and, 
wherever  possible,  to  start  from  familiar  facts  and  gradu- 
ally lead  up  to  less  obvious  ones.  In  this  part  of  the  task, 
which  was  really  the  most  difficult,  I  have  had  so  much 
aid  from  my  wife's  experience  in  teaching  young  pupils, 
that  her  name  propedy^has  a  uUice  on  the  title-page. 


iv  PREFACE. 

We  both  desire  to  express  our  obligations  to  Miss 
Frances  F.  Bauman,  who  placed  freely  at  our  disposal  the 
results  of  her  long  and  eminently  successful  experience 
in  teaching  Physiology  to  children. 

As  appendices  to  certain  of  the  chapters  there  are 
practical  directions  for  the  illustration  of  various  facts 
in  Anatomy  and  Physiology,  which  can  be  shown  to  pu- 
pils without  any  special  apparatus,  or  any  material  not 
easily  obtained. 

Particular  attention  has  been  given  to  the  action  on 
the  body  of  the  more  commonly  abused  stimulants  and 
narcotics,  especially  alcohol. 

H.  NEWELL  MARTIN. 

JOHNS  HOPKINS  UNIVERSITY,  June  30,  1884. 


CONTENTS. 


I.  The  General  Plan  on  which  the  Human  Body  is  Built.. .  i 

II.  The  Skeleton 12 

III.  The  Structure,  Composition,  and  Hygiene  of  the  Bones.  24 

IV.  The  Organs  of  Movement :  Muscles  and  Joints 35 

V.  Care  of  the  Joints  and  Muscles 48 

VI.  The  Skin 59 

VII.  Hygiene  of  the  Skin.— Animal  Heat.— Clothing 71 

VIII.  Foods 81 

IX.  Stimulants 91 

X.  Digestion 98 

XI.  Digestion,  concluded no 

XII.  Hygiene  of  the  Digestive  Organs 123 

XIII.  The  Circulation 133 

XIV.  Hygiene  of  the  Circulatory  Organs 153 

XV.  Respiration 163 

XVI.  Hygiene  of  the  Respiratory  Organs 176 

XVII.  The   Kidneys 185 

XVIII.  The  Nervous  System 190 

XIX.  Hygiene  of  the  Nervous  System 203 

XX.  Narcotics 216 

XXI.  The  Sense  Organs 223 

XXII.  Summary  concerning  the  Action  of  Alcohol  on  Body, 

Mind,  and  Character 240 

Glossary 247 

Index 255 


THE  HUMAN  BODY.      *'- 


CHAPTER  I. 

THE  GENERAL  PLAN  ON  WHICH  THE  HUMAN  BODY  IS 

BUILT. 

1.  Why  we  should  Learn  about  our  Bodies. — Suppose 
you  had  given  to  you  a  delicate  instrument,  such  as  a 
watch:  you  would  desire  to  be  told  something  of  the  way 
it  was  made,  how  it  was  to  be  used,  and  what  was  apt  to 
harm  it.  Even  a  little  knowledge  of  these  things  would 
help  you  to  take  better  care  of  the  watch. 

Now  every  one  of  us  is  responsible  for  the  care  of  a 
body  made  up  of  many  more  parts  than  we  find  in  a 
watch,  and  any  of  them  liable  to  be  injured  in  number- 
less different  ways.  If  all  the  parts  work  well  we  are  in 
health,  able  to  enjoy  our  lives,  do  our  work,  and  aid  those 
who  are  less  fortunate.  If  we  lose  our  health  we  not 
only  can  do  less  and  enjoy  less  ourselves,  but  are  likely 
to  become  a  burden  upon  others.  It  is  therefore  one  of 

I.  If  you  have  a  watch,  what  ought  you  to  know  of  it,  and  why? 
What  is  the  nature  of  the  machine  given  to  every  human  being  to 
take  care  of?  If  it  is  kept  in  good  order,  what  is  the  result?  If  not? 
What  then  is  our  duty  with  regard  to  it  ? 


ANATOMY  AND  PHYSIOLOGY. 

our  first  duties  to  learn  enough  about  our  bodies  to  be 
able  to  avoid  doing  things  likely  to  harm  them,  or  neg- 
lecting to  do  that  which  is  for  their  welfare. 

2.  What  Anatomy  is. — We  could  not  look  at  the  watch 
without  seeing  that  it  was  made  up  of  different  pieces,  as 
case,  and  face,  $iid  hands;  and  a  glance  at  the  works  in- 
side w<?ulc!  shpw>  us  that  dozens  of  parts,  such  as  wheels, 
£rid<  pivots,  arid-  springs,  and  screws,  without  which  the 
portions  we  see  on  the  outside  would  be  useless,  were 
fixed  together  in  a  special  way  to  make  the  watch. 

Likewise,  on  looking  at  the  outside  of  the  body  you 
easily  perceive  head,  and  neck,  and  trunk,  and  arms,  and 
legs;  and  if  you  could  see  into  the  inside  you  would  find 
hundreds  of  other  parts,  which  move  the  parts  you  see 
and  make  them  useful.  The  science  which  teaches  us 
the  shape  and  size  of  all  the  parts  of  the  body,  where 
they  are  placed  in  it,  and  how  they  are  joined  together, 
is  named  Hitman  Anatomy. 

3.  What  Physiology  is. — On   examining  the  parts   of 
which  a  watch  is  made  we  find  that  each  has  its  use:  the 
case  to  protect  the  works,  the  glass  to  let  us  see  the  face 
and  yet  keep  out  dust,  the  hands  to  show  the  hour,  the 
spring  to  keep  it  going,  and  so  forth. 

In  like  way  it  is  found  that  the  various  parts  of  the 
body  have  their  uses:  as  the  eyes  to  see,  the  mouth  to 
eat,  the  legs  to  walk  with.  The  science  which  teaches 
the  uses  of  all  the  parts  of  the  body,  more  particularly  of 
its  inner  parts,  is  named  Human  Physiology. 

2.  What  do  we  easily  find  out  on  examining  a  watch?     In  this  re- 
spect how  may  the  body  be  compared  to  a  watch?     What  is  Humai. 
Anatomy  ? 

3.  Why  are  there  many  parts  in  a  watch  ?     In  the  body?    What  is 
Human  Physiology  ? 


ttYGtENS.  3 

4.  What  Hygiene  is.— Lastly,  when  you  had  learned 
something  of  how  the  watch  was  made  and  what  each  part 
of  it  had  to  do, you  would  know  that  certain  things  must 
injure  it;  that  it  should  be  kept  dry  lest  the  steel  springs 
rust,  and  that  the  case  must  be  kept  closed  to  prevent 
dust  and  grit  from  getting  into  the  works.  You  might 
also  be  told  some  things  which  it  would  take  you  a 
longer  time  to  find  out  for  yourself;  as,  for  example,  that 
if  the  watch  is  to  be  a  good  time-keeper  it  must  be  regu- 
larly wound  up,  and  not  at  one  time  one  day  and  at 
another  the  next,  or  perhaps  quite  forgotten  a  third. 

So,  without  learning  much  Anatomy  and  Physiology 
you  will  readily  see  that  certain  things  must  be  bad 
for  your  body:  such  as  getting  wounds  that  will  cause 
great  loss  of  blood,  or  going  without  food.  The  harm- 
fulness  of  other  things  it  might  take  you  a  long  time  to 
find  out  by  yourself;  as,  for  example,  that  by  breathing 
foul  air  or  taking  too  little  sleep,  eating  imprudently  or 
drinking  what  is  called  "spirits,"  you  might  very  easily 
injure  your  body  beyond  cure.  Unless  you  were  warned 
you  would  probably  not  discover  the  danger  until  too 
late  to  avert  it. 

Just  as  a  watchmaker  could  save  you  a  great  deal  of 
time  and  risk  by  giving  the  results  of  his  experience  as 
to  the  best  way  to  manage  a  watch,  physicians  and  others 
who  have  made  a  study  of  what  is  good  and  what  bad 
for  the  human  body  can  save  us  much  labor  and  danger 
by  telling  what  they  have  found  out.  The  science  which 


4.  Having  examined  a  watch,  what  would  at  once  occur  to  you  about 
its  preservation  ?  What  studies  teach  you  that  certain  things  would 
be  bad  for  your  body?  Name  some  injurious  habits  that  the  ex- 
perience of  others  warns  you  to  avoid.  What  is  meant  by  Hygiene? 


4  ORGANS  AND   TISSUES. 

teaches  what  is  good  and  what  hurtful  to  our  bodies — in 
other  words,  how  we  may  best  preserve  our  health — is 
known  as  Hygiene. 

5.  Organs  and  Functions. — The  separate  parts  of  which 
the  body  is  made  up  are  called  organs:  thus  the  eye  is  the 
organ  of  sight,  the  teeth  are  organs  of  chewing,  the  stom- 
ach is  an  organ  of  digestion.     The  use  of  any  organ   is 
spoken  of  as  its  function :  thus  the  function  of  the  eye  is 
seeing,  of  the  ear  hearing,  of  the  hand  grasping. 

6.  The  Structure  of  Organs. — The  human  body,  like  a 
watch,  not  only  has  numerous  parts,  but  these  parts  are 
made  of  different  materials.     Taking  the  hand,  for  ex- 
ample, we  observe  on  the  outside,  skin,  nails,  and  hairs. 
If  the  skin  were  removed  we  should  see  below  it  some 
fat,  just  like  that  in  beef  and  mutton.     Under  the  fat,  in 
the  ball  of  the  thumb  you  would  find  some  red  flesh, 
called  muscle,  which  answers   to  the  lean  of  meat.     Be- 
neath all  the  rest  would  be  white  hard  bones.     At  the 
finger-joints  where  the  ends  of  separate  bones  come  near 
together  you  would  see  covering  each  a  thin   layer  of 
gristle  or  cartilage.     And  binding  together  the  skin  and 
fat  and  muscles  and  bones  would  be  found  a  stringy  sub- 
stance which,  as  it   unites  all  the  rest,  is  called  the  con- 
nective material. 

7.  Tissues. — Each  kind  of  material  used  in  constructing 
the  body  is  called  a  tissue:  and  each  tissue  has  its  own 
peculiar  properties.     Connective  tissue  is  tough  and  suited 


5.  What  is  an  organ  ?     Give  examples.     What  is  a  function  ?     Il- 
lustrate. 

6.  What  is  meant  by  the  structure  of  an  organ  ?     Describe  the 
structure  of  the  hand. 

7.  What  is  a  tissue?     Name   and    describe  some  tissues.     Name 
some  liquids  of  the  body. 


THE  PLAN-  ON    WHICH  MAN'S  BODY  IS  BUILT.     5 


to  bind  parts  together.  Bony 
tissue  is  stiff  and  useful  to  sup- 
port softer  parts.  Cartilage  tis- 
sue is  elastic  and  forms  admir- 
able springy  cushions  between 
the  hard  bones.  Muscle  tissue 
has  power  to  move  parts  to  which 
it  is  joined;  and  so  on. 

In  addition  to  the  solid  tissues, 
liquids  form  part  of  the  body: 
as  the  blood  which  we  see  flow 
from  a  cut  finger,  and  the  saliva 
which  moistens  the  mouth. 

8.  The  General  Plan  on  which 
the  Body  is  Built.—  If  a  man's 
body  were  sawed  in  two  down 
the  middle,  so  as  to  separate 
it  into  right  and  left  halves,  we 
should  see  something  like  Fig.  i, 
if  we  looked  at  the  cut  surface 
of  the  right  half.  On  examining 
the  figure  you  see  that  there  are  Fig.  i.—  A  section  along  the  mid- 

die  of  head,  neck,  and  trunk.    6t 

tWO    Chief    Cavities    Or    chambers   the  chest,  and   c,   the  abdominal 

division  of  the  ventral  cavity  sep- 

in  the  body,  having  between  them  arated  by  the  diaphragm,  d.   «', 

the  enlarged  upper  end  of  the  dor- 

the  row  of  bones  ,  e;  these  bones  -}, 
together   form   the  back-bone   or 
spine.     The    chamber,   B,   C,   in 


f  f    ,1       i        *     i  .  ,     the  nose.     o.   the  mouth.    /,   the 

front    Of    the  back-bone    IS    much   lungs;   the  tube  leading  down  to 
Al       .  .     .  ,       .  them   is  the    windpipe.       A,   the 

the  larger;  it  is  named  the  ve/i-  heart.  /,  the  stomach;  the  tube 

leading  down  to  it  is  the  gullet; 
tral  cavity.  1  he  Other  Chamber,  the  tube  passing  from  the  stomach 

to  the  lower  end  of  the  trunk  is  the 
a,  a'  is  the  dorsal  Cavity.  intestine.  £,  a  kidney.  *,  the 

sympathetic  nervous  system. 

8.  How  does  the  plan  on  which  a  watch  is  made  compare  with  that 
on  which  the  body  is  constructed  ?  In  a  human  body  cut  down  the 
middle  what  chief  divisions  would  you  find  ? 


I 
6  THORAX  AND   ABDOMEN. 

9.  The   Ventral   Cavity,   as  you    perceive    in    the    fig- 
ure,   does    not    reach    up    into    the    neck    or    head.    .  It 
exists  only  in  the    trunk   of   the   body,  and   is   divided 
into    an    upper    story,    B,    the    chest   or    thorax,    and    a 
lower   story,    C,   the  abdomen,   by   a   partition,   d,   which 
forms  the  floor  of  the  thorax  and  the  ceiling  of  the  ab- 
dom£n.     This  partition  is  the   diaphragm.     How  far  in 
your  own  body  the  chest-cavity  extends  you  can  find  out 
pretty  accurately  by  beginning  at  the  bottom  of  the  neck 
and  feeling  down  along  the  middle  of  the  front  of  your 
trunk   till    you   feel   no   more  bones    through    the  skin: 
that  level  marks  the  bottom  of  the  thorax. 

10.  Contents  of  the  Thorax. — On  Fig.  i  you  will  also  see 
that  the  mouth,  o,  and  the  nose,  /,  join  behind,  and  that 
from  the  place  of  meeting  two  tubes  run  down  the  neck. 
The  front  one  of  these  tubes  is  the  windpipe  or  trachea; 
after  entering  the  thorax  it  ends  in  the  lungs,  I.     In  the 
thorax  is  also  placed  the  heart,  h. 

11.  Contents  of  the  Abdomen. — The  second  of  the  tubes 
above  referred  to  is  the  gullet  or  oesophagus.     It  runs  right 
on  through  the  chest  and  diaphragm  into  the  abdomen, 
and  there  opens  into  the  stomach,  f. 

The  air  we  take  in  when  breathing  goes  along  the 
windpipe  to  the  lungs,  but  no  further:  the  food  and 
drink  which  we  swallow  take  a  longer  road  along  the 
gullet  to  the  stomach. 

In  addition  to  the  stomach,  the  liver,  the  intestines  or 
bowels,  and  the  kidneys,  k,  lie  in  the  abdomen. 

9.  Where  is  the  ventral  cavity  ?     Name  its  divisions.     The  parti- 
tion.    How  can  you  trace  the  chest  or  thorax  in  your  own  body  ? 

10.  Name  contents  of  thorax. 

11.  What  is  the  course  of  the  gullet?     Its  use  ?     Use  of  the  wind- 
pipe ?     Name  the  organs  which  lie  in  the  abdomen. 


CONTENTS  OF   THORAX  AND  ABDOMEN.  / 

12.  What  would  be  seen  if  the  front  of  the  Thorax  and 
Abdomen  were  cut  away. — This  is  represented  in  Fig.  2. 
Stretching  across  from  side  to  side  is  seen  the  diaphragm, 


Fig.  2.— The  trunk  of  the  body  opened  from  the  front  to  expose  the  contents  of 
the  ventral  cavity.  z«,  the  diaphragm  ;  /«,  /»',  the  lungs  ;  h,  the  heart ;  ma,  the 
stomach;  mi,  the  spleen;  ne,  «<,  the  membrane  (great  amentum)  which  lies  in 
front  of  the  intestines  and  kidneys. 

12.  Name  the  parts  which  would  be  exposed  if  the  front  wall  of 
chest  and  abdomen  were  cut  away.  State  their  positions. 


8  VERTEBRATE  ANIMALS. 

zz.  Above  the  diaphragm,  in  the  thorax,  are  the  lungs^ 
lu,  lu.  Between  the  lungs  is  the  heart,  h,  partly  covered 
by  fat  and  other  things.  Below  the  diaphragm  is  the 
liver,  le,  le',  the  stomachy  ma,  and  the  spleen,  mi.  Hanging 
down  from  the  stomach  is  a  sort  of  apron,  ne,  ne;  if  it 
were  lifted  up  we  should  find  behind  it  the  intestines  and 
the  kidneys. 

13.  The  Dorsal  Cavity  (a,  a',  Fig.  i)  is  found  in  the  head 
and  neck  as  well  as  in  the  trunk  of  the  body.     If  the  back 
or  top  of  a  man's  head  were  cut  away  the  upper  end  of 
the  dorsal  cavity  would  be  opened  and  we  should  find  it 
to  be  a  large  chamber  having  the  brain,  N',  in  it.     In  the 
neck  and  trunk  the  dorsal  cavity  is  a  narrow  tube  con- 
taining in  its  upper  two-thirds  the  spinal  cord,  N. 

14.  Man  is  a  Vertebrate  Animal. — The  presence  of  the 
ventral  and  dorsal  cavities  with  a  hard  partition  between 
them  is  a  chief  fact  in  the  anatomy  of  the  human  body : 
it  shows  that  man  is  a  vertebrate  animal,  that  is  to  say,  is 
a  back-boned  animal,  and  belongs  to  the  same  great  group 
as  fishes,  reptiles,  birds,  and  beasts.     Worms,  clams,  and 
insects  are  invertebrate  animals,  that  is,  have  no  back-bone. 

15.  Man's  Place  among  Vertebrates. — We   have   seen 
that  man  is  a  vertebrate,  or  back-boned  animal.    Though 
all   vertebrates  are  alike  in    the  general  plan  of   their 
structure,  there  are  such  differences  that  zoologists  di- 
vide them  into  classes.     The  most  important  of  these 


13.  Where  does  the  dorsal  cavity  lie  1     Name  its  contents  and  give 
their  position. 

14.  Why  is  man  a  vertebrate  animal?     Name   some  other  verte- 
brates.    How  are  vertebrates  distinguished  from  invertebrates  ?  Give 
examples  of  invertebrate  animals. 

15.  Why  are   vertebrates   divided    into  clashes?     To  which    class 
does  man  belong?     Name  some  other  mammalia.     How  do  mamma- 
lia differ  from  other  vertebrates  ? 


CHEMISTRY  OF  HUMAN  BODY.  9 

classes  is  the  mammalia,  to  which  man  belongs.  Ordinary 
four-footed  beasts,  and  monkeys,  are  also  mammalia. 
The  mammalia  differ  from  all  fishes,  reptiles,  and  birds, 
first,  in  the  possession  of  organs,  the  mammary  glands, 
which  provide  milk  for  the  young;  second,  in  possessing 
hair;  third,  in  having  the  chest  separated  from  the  ab- 
domen by  a  diaphragm. 

16.  The  Intellect  of  Man  makes  him  superior  to  any 
other  animal  and  supreme  in  the  world. 

His  power  to  form  conceptions  of  right  and  wrong  and  his 
knowledge  of  moral  responsibility  give  him  yet  greater  supe- 
riority. But  as  a  material  object  only,  do  anatomists  study 
man's  body,  and  they  therefore  classify  it  among  the 
bodies  of  other  animals  according  as  it  differs  from  or 
resembles  them  in  the  arrangement  of  its  parts. 

17.  Chemistry  of  the  Body. — Suppose  you  put  a  green 
stick  into  the  fire:  what  happens?     At  first  it  hisses  and 
gives  off  steam;  then  it  begins  to  burn;  if  you  draw  it 
out  when  half  burned  you  find  it  a  black  mass  of  charcoal; 
if  you  put  it  back  you  find  most  of  the  charcoal  will  burn 
away,   but   some  ashes   will  be  left  which  you  cannot 
make  burn.     If,  instead  of  a  green  piece  of  wood,  a  man's 
body  be  burned,  we  find  the  same  results.     From  this 
we  learn  (i)   that   the  body  contains  water;  (2)  that  it 
contains  solid  things  which  will  burn;  (3)   that  it  con- 
tains solid  matters,  the  ash,  which  will  not  burn. 

16.  What  makes  man  superior  to  all  other  animals  ?     What  gives 
him  yet  greater  superiority  ?     From  what  standpoint  is  man  studied 
by  anatomists?     How  classified  ? 

17.  What  would  be  the  action  of  fire  on  green  wood?     On  man's 
body?     Hence  what  do  we  learn?    What  name  is  given  the  materials 
which    burn    up?     What    those  which  will    not    burn?     Of  what    is 
every  tissue  composed  ?     In  which  do  we  find  most  water  ?     Mineral 
matter?     Animal  matter? 


10  SUMMARY. 

The  things  going  to  make  up  the  body  and  capable  of 
being  burned  are  known  as  animal  matters;  the  ashes  are 
mineral  matters.  In  every  tissue  of  the  body  there  are 
water,  animal  matter  and  mineral  matter.  In  some  a 
great  deal  of  water,  as  in  the  blood;  in  others  a  great 
deal  of  mineral  matter,  as  in  the  bones  and  teeth,  which 
owe  their  hardness  to  lime;  in  still  others  a  great  deal  of 
animal  matter,  as  in  fat  and  muscle:  but  everywhere 
some  of  all  three. 

18.  Summary. — Anatomy  is  concerned  with  the  form 
and  structure  of  the  parts  of  the  body. 

Physiology  with  the  uses  of  the  parts  and  the  ways  in 
which  they  work. 

Hygiene  with  the  conditions  of  life  which  promote  the 
health  of  the  body. 

The  materials  of  the  body  are  hard  or  soft,  solid  or 
liquid,  and  are  fitted  for  different  purposes. 

Tissue  is  the  name  given  to  each  of  the  materials, 
whether  blood,  bone,  muscle,  fat,  or  any  other. 

The  organs  are  formed  of  tissues  combined  in  various 
ways.  Each  organ  has  its  own  particular  duty,  or  func- 
tion, which  in  health  it  performs  in  harmony  with  all  the 
others. 

Vertebrates  are  animals  having  back- bones — such  as 
man,  beasts,  birds,  reptiles,  and  fishes.  Their  bodies 
contain  two  main  cavities,  dorsal  and  ventral.  In  the 
dorsal  cavity  are  the  brain  and  spinal  cord.  The  ventral 
cavity  contains  lungs,  heart,  stomach,  liver,  intestines, 
and  kidneys. 

18.  What  does  anatomy  deal  with?  Physiology?  Hygiene? 
What  have  we  learned  of  the  materials  of  the  body  ?  Of  tissue  ?  Of 
the  organs  ?  Of  vertebrates  ?  Of  invertebrates  ?  Of  mammalia  ?  Of 
the  chemical  constituents  of  the  body? 


SUMMAR  Y.  1 1 

Invertebrates  are  animals  having  no  back-bones — such  as 
worms,  clams,  and  insects. 

Mammalia  is  the  highest  of  the  several  classes  of  verte- 
brates and  includes  man,  monkeys,  and  four-footed 
beasts.  It  is  characterized  by  the  presence  of  mammary 
glands;  by  the  fact  that  the  ventral  cavity  is  separated 
into  chest  and  abdomen  by  the  diaphragm;  and  by  having 
more  or  less  of  the  surface  covered  with  hair. 

Water,  animal  matters  and  mineral  matters  compose  the 
body.  If  it  be  burned  the  animal  matters  are  consumed; 
the  mineral  matters  remain  in  the  form  of  ashes. 


CHAPTER   II. 
THE   SKELETON. 

1.  The  Skeleton.— By  the  skeleton  of   any  animal  we 
usually  mean   those  hard    parts    which    remain    behind 
when  the  softer  parts  have  decayed;   as  the  shell  of  a 
clam  or  crab,  or  the  bones  of  a  bird  or  beast.    In  our  own 
bodies,  bones  form  the  chief  part  of  the  skeleton;  but  other 
things  help.    A  very  young  infant  has  a  skeleton,  but  this 
skeleton  is  made  for  the  most  part  of  cartilage,  or  gristle, 
and  not  of  bone.     As  the  child  grows,  more  and  more 
bone  takes  the  place  of  the  cartilage;  but  even  in  old  age 
some  cartilage  remains.     Moreover,  a  skeleton  consists 
not  merely  of  all  the  bones  of  a  body,  but   of  all    the 
bones    united   together  in  their  proper  places.     In  our 
bodies  they  are  bound  together  by  tough  stringy  connec- 
tive tissue.     The  skeleton  of  the  living  body,  as  distin- 
guished from  a  dead  skeleton  made  of  dry  bones  joined 
together  by  wires,  is  therefore  made  up  of  three  different 
things;  namely,  bones,  cartilages,  and  connective  tissue. 

2.  The  Bones,  two  hundred    and  six  in    number  (see 
table,  p.  22),  form  the  hardest,  and  stiffest,  and  heaviest 


1.  What  is  a  skeleton  ?     What  change  takes  place  in  the  skeleton 
of  a  child  as  it  grows  ?     How  are  the  bones  of  a  skeleton  put  together  ? 
What  are  the  materials  of  the  living  human  skeleton  ? 

2.  Number  of  bones   in  the  skeleton  ?     What  part  of  it  do   they 
make?      How   do  they  provide  support?     Protection?      How  con- 
cerned in  movement  ? 


PLATE   I.-THE  BONES,  JOINTS,  AND  LIGAMENTS 


EXPLANATION  OF  PLATE  I. 

A  front  view  of  a  human  skeleton  with  the  ligaments  and  some  of 
the  cartilages  in  place. 
For  the  names  of  the  bones  see  the  description  of  figure  3. 

a  Ligaments  of  the  Elbow-Joint. 

6  The  Ligament  which  is  connected  to  the  ventral  surfaces  of  the  bodies  of 

the  Vertebrae. 

e  Ligament  connecting  the  Innominate  Bone  to  the  Spine. 
/  Ligament  connecting  the  Innominate  Bone  to  the  Sacrum. 
g  The  Ligaments  of  the  Wrist-Joint. 
h  The  connective- tissue  Membrane  which  fills  up  the  ineerval  between  the  two 

bones  of  the  Forearm. 
I  A  similar  Membrane  between  the  two  bones  of  the  Leg,  and,  lower  down, 

Z,  ligaments  of  the  Ankle-joint. 

k  A  connective-tissue  Membrane  which  fills  up  a  hole  in  the  Innominate  Bone. 
n  Ligaments  of  the  Knee-Joint. 
o  o  Ligaments  of  the  Toes  and  Fingers. 
p  Capsular  (bag -like)  Ligament  of  the  Hip  Joint. 
q  Capsular  Ligament  of  the  Shoulder-Joint. 


CARTILAGE— CONNECTIVE    TISSUE.  13 

part  of  the  skeleton.  United  in  various  ways,  they  pro- 
vide a  strong  framework  which  supports  the  softer 
organs,  and  in  some  places,  as  the  skull  (Fig.  6)  and 
thorax  (Fig.  5),  make  strong  boxes  or  cages  in  which 
delicate  organs,  such  as  the  brain  or  lungs,  lie  safe.  The 
bones  are  also  concerned  in  the  movements  of  the  body; 
nearly  all  muscles  pull  first  on  some  bone  or  other,  and 
when  the  bone  is  made  to  move,  it  of  course  carries  with 
it  the  surrounding  soft  parts. 

3.  Cartilage  is  what  we  know  in  meat  as  gristle :  it  is 
stiff  enough  to  keep  its  shape,  but  can  be  bent  with  tol- 
erable ease;  it  is  also  elastic,  so  that  it  springs   back  to 
its  proper  shape,  like  a  piece  of  whalebone,  as  soon  as 
the  force  which  has  bent  it  ceases  to  act.     You  can  easily 
feel  on  your  nose  the  difference  between  bone  and  car- 
tilage.   The  skeleton  of  that  part  of  it  near  the  forehead 
is  made  of  bone,  and  that  of  the  lower  part  of  cartilage. 
We  can  push  the  tip  of  the  nose  to  either  side,  or  up  and 
down,  but  when  we  stop  pressing,  it  returns  to  its  place. 
The  skeleton  of  that  part  of  the  ear  which  projects  from 
the  side  of  the  head  is  also  made  of  cartilage. 

Cartilage  is  used  in  parts  of  the  skeleton  which  have 
to  be  moderately  stiff,  but  at  the  same  time  pliable  and 
elastic. 

4.  Connective  Tissue  is  used  for  several  different  pur- 
poses in  the  body.     To  understand  this,  let  us  imagine 
a  quantity  of  very  fine  strands  of  silk,  some  twisted  into 

3.  What  is  cartilage  ?     Its  properties?     How  used  in  the  nose  ?    In 
the  ear  ?     Throughout  the  skeleton  ? 

4.  To  what  may  connective  tissue  be  compared  ?     Name  and  char- 
acter of  its  threads  ?     How  are  the  cords  made?     The  membranes? 
The  loose  portion  ?     Where  do  we  find  networks  of  connective  tis- 
sue?    Give  an  example. 


14    ACTION  OF  ALCOHOL  ON  CONNECTIVE  TISSUE. 

strong  cord  or  rope,  some  woven  into  firm  bands,  some 
left  in  loose  masses,  and  some  made  up  into  fine  net- 
work. Connective  tissue  consists  of  threads,  called 
fibres,  which  are  much  tougher  and  finer  than  any  strand 
of  silk.  In  some  parts  of  the  body  these  threads  are 
united  to  form  cords  named  ligaments,  which  bind  bones 
together.  Elsewhere  the  fibres  are  woven  into  bands  or 
membranes  which  surround  and  support  various  parts. 
Lying  in  the  crevices  between  different  organs,  forming 
a  soft  packing  for  them,  we  find  loose  fluffy  bundles  of 
connective  tissue.  Finally,  very  fine  networks  of  this 
tissue  run  all  through  most  of  the  organs,  like  the  veins 
or  ribs  through  the  leaf  of  a  plant,  and  support  and 
unite  their  parts.  If  you  watch  the  cook  cut  up  a  piece 
of  suet,  you  will  see  the  stringy  connective  tissue  which 
penetrates  it  in  all  directions,  and  which  must  be  re- 
moved from  the  fat  because  it  will  not  melt  in  cook- 
ing. 

5.  Action  of  Alcohol  upon  Connective  Tissue. — All  intoxi- 
cating liquors,  such  as  wine,  brandy,  whiskey,  beer,  etc., 
contain  alcohol  and  are  known  as  alcoholic  drinks.     One 
very  serious  change  in  the  body  frequently  produced  by 
drinking  such,  is  an  excessive  growth  of  the  connective- 
tissue  networks,  especially  in  the  liver  and  the  kidneys. 
The  tissue  becoming  too  abundant  crushes  and  slowly 
destroys  the  chief  liver  and  kidney  substance  which  it 
was  meant  to  protect  and  support.     The  results  are  in- 
curable diseases.     (See  pp.  132,  189.) 

6.  The  Bony  Skeleton  (Fig.  3),  like  the  body  itself,  may 
be  described    as  consisting  of   head,   neck,   trunk,  and 

5.  What  are  alcoholic  drinks  ?   How  do  they  affect  connective  tissue? 

6.  Of  what  parts  does  the  bony  skeleton  consist  ? 


THE  SKELETON. 


FIG.  3.— The  bony  skeleton,  <z,  <*,  the  skull;  c,  #,  the  back-bone;  d,  the  breast- 
bone; w,  the  collar-bone;  /,  the  humerus;  y,  the  ulna;  r^  the  radius;  A,  the  carpal 
bones;  z",  the  metacarpal  bones;  £,  the  phalanges  of  the  fingers;  j,  the  hip-bone; 
r,  the  thigh-bone;  7,  the  knee-pan;  /,  the  shin-bone  or  tibia;  m,  the  fibula;  *,  the 
tarsal  bones;  o,  the  metatarsal  bones;  /,  the  phalanges  of  the  toes. 


THE  BACK-BONE. 

limbs.  Its  central  part,  which  bears 
all  the  rest,  is  a  stout,  bony  pillar,  the 
back-bone,  c,  e,  on  the  top  of  which  is  the 
skull. 

7.  The  Back-Bone,  Vertebral  Column, 
or  Spine,  is  represented  in  side  view  in 
Fig.  4.  Its  upper  part  is  made  of 
twenty-four  short  thick  bones  piled 
one  upon  another,  and  each  called  a 
vertebra.  Between  each  pair  of  verte- 
brae there  is  placed  during  life  an  elas- 
tic cartilaginous  cushion.  The  lower 
part  of  the  spine  consists  of  two 
bones;  a  large  one,  the  sacrum,  extend- 
ing from  Si  to  Coi;  and  a  much  small- 
er, the  coccyx,  reaching  from  Coi  to  the 
end. 

Projecting  from  the  back  of  each 
vertebra  (to  the  right  in  the  figure) 
is  a  bony  bar,  called  its  spinous  process. 
Through  the  skin  along  the  middle  of 
the  back  we  can  feel  the  tips  of  these 
processes,  and  it  is  their  presence  which 
has  given  the  name  spinal  column  to 
the  whole. 

A  canal  runs  through  the  whole  back- 
FIG.  4. -The  spinal  bone  except  the  coccyx,  and  opens  into 

column  viewed  from  the  ,  T       •          i 

left  side.   Ci-7,  the  ver-   the    skull-chamber    above.     It   is    the 

tebraeof  the  neck;  Z>i-ia,  •,./**•          \ 
the  vertebrae  behind  the  lower  part  of  the  dorsal  cavity  (a,  ^  Ig.  l), 
thorax.    L 1-5,  the  verte- 
brae of  the  loins;  Si  to  and,  as  we  have  already  learned,  con- 

Coi,  the  sacrum;  €01-4, 

the  coccyx.  tains  the  spinal  cord. 

7.  What  other  names  has  the  back-bone  ?     Divisions  of  its  upper 
part  ?    Lower  part  ?    What  is  the  spinous  process  ?    The  dorsal  cavity  ? 


USES  OF  BACK-BONE.  I? 

8.  Uses  of  the  Mode  of  Structure  of  the  Spinal  Column. — 

The  elastic  cushions  between  the  vertebrae  make  the 
whole  column  springy  and  prevent  the  transmission  of 
sudden  jars  along  it.  By  this  means  the  soft  brain,  car- 
ried in  the  skull  on  its  top,  and  the  spinal  cord  lying  in 


FIG.  5.— The  skeleton  of  the  thorax,  with  some  of  the  vertebrae  of  the  neck  and 
loins,  a,  lower  neck  vertebrae;  6,  the  first  rib;  c,  the  collar-bone;  rf,  third  rib;  f, 
seventh  rib;  £-,  last  loin-vertebra;  A,  the  breast-bone;  /',  the  shoulder-blade. 

it,  are  protected  from  injury  in  running  and  jumping. 
These  cushions  also  allow  of  a. little  bending  between 
each  pair  of  vertebrae,  so  that  the  spine  as  a  whole  may 
be  bent  a  good  deal.  But  no  sharp  bend,  such  as  would 
nip  the  spinal  cord,  which  lies  inside  it,  can  take  place 
at  any  one  point. 

8.  Of  what  use  is  the  cartilage  between  the  vertebra?  in  running  or 
jumping?     In  bending? 


1 8        RIBS  AND   STERNUM.— SKULL.— SUTURES. 

9.  The  Ribs  and  Breast-Bone  (Fig.  5). — The    ribs   are 
twenty-four  slender  curved  bones,  twelve  on  each  side 
of  the  chest.    Every  rib  is  attached  behind  to  a  vertebra, 
the  top  one  to  the  first  vertebra   below  the  neck.     In 
front,  each  rib  ends  in  two  or  three  inches  of  cartilage. 
The  breast-bone  or  sternum,  h,  lies  in  front  of  the  chest. 
Attached  to  its  sides  are  the  cartilages  of  most  of  the 
ribs.     The  two  lowest  ribs  are  not  joined  to  the  breast- 
bone and  are  sometimes  called  the  free  QV  floating  ribs. 

10.  The  Skull  (Fig.  6)  is  made  up  of  twenty-nine  bones 
(see  table,  p.  22);  those  behind  and  above  arranged  to 
form  the  brain-box;  and  those  in  front,  to  support  the 
face. 

The  organs  of  four  of  our  senses,  viz.,  those  of  hear- 
ing, sight,  smell,  and  taste,  are  also  protected  by  the 
skull-bones. 

11.  The  Sutures. — Except  the  lower  jaw-bone,  which  is 
attached  to  the  rest  of  the  skull  by  a  joint,  to  let  us  open 
and  close  our  mouths,  nearly  all  the  skull-bones  are  very 
firmly  united.     In  most  cases  the  union  is  by  a  dovetail- 
ing, like  that  used  by  cabinet-makers.     Each  bone  has 
its  edge  notched  and  fits  accurately  to  the  edge  of  the 
next.     This  sort  of  junction  between  bones  is  called  a 
suture.     It  is  well  seen  in  Fig.  6  between  the  bone  Pr 
and  those  in  front  of,  behind,  and  below  it. 

12.  How  the  Brain  is  Protected. — The  dome-like  form 


9.  What  is  the  number  and  form   of  the   ribs  ?    How   attached 
behind?     How  do  they  end  in  front?     How  attached  to  the  breast, 
bone  ?     Floating  ribs  ? 

10.  How  many  bones  in  the  skull?     Use  of  those  behind  and  above ? 
Those  in  front  ?    What  other  organs  do  they  protect  ? 

IT.  How  is  the  lower  jaw-bone  attached?     Union  of  other  skull- 
bones  ?    'What  is  a  suture  ? 

12.  What  is  the  advantage  of  the  dome-like  form  of  the  skull?    II- 


THE   SKULL. 


of  the  crown  of  the  head  gives  it  great  strength.  This 
you  will  realize  if  you  take  an  egg  by  its  ends  between 
finger  and  thumb,  and  try  to  crush  it:  you  will  find  that 


Tsp 


Md 


FIG.  6. — Side  view  of  the  skull.  Pr,  parietal  bone;  0,  occipital  bone;  T,  tem- 
poral bone;  S,  sphenoid  bone;  f,  frontal  bone;  Z,  malar,  or  cheek-bone;  N,  nasal 
bone;  £,  ethmoid  bone;  L,  lachrymal  bone;  MX,  upper  jaw-bone;  Md,  lower  jaw- 
bone. 

lustrate.  Describe  the  outer  layer  of  the  bones  on  the  sides  and  top 
of  the  brain.  The  next.  The  innermost.  To  what  may  this  ar- 
rangement of  the  skull-bones  be  compared  ? 


20  SKELETON  Of   UPPER  LIMBS. 

you  cannot,  although  egg-shell  is  thin  and  brittle.  The 
bones  on  the  sides  and  top  of  the  brain-case  are  made 
up  of  three  layers:  an  outer,  tough  and  fitted  to  bear 
without  breaking,  blows  from  a  heavy  blunt  object.  Then 
comes  a  much  softer  layer  which  deadens  any  jar  that 
might  result  from  a  blow  on  the  head,  and  hinders  its 
transmission  to  the  brain.  Inside  is  a  layer  of  very  hard 
bony  matter,  almost  like  glass,  and  admirably  fitted  to 
stop  or  turn  aside  any  pointed  instrument  which  might 
have  penetrated  the  outer  layers.  If  you  turned  upside- 
down  a  thin  china  teacup,  wrapped  around  it  a  covering  of 
raw  cotton,  and  over  this  put  a  thin  casing  of  tough  wood, 
anything  placed  under  the  cup  would  be  protected  from 
blows,  jars,  and  piercing,  much  as  your  brain  is  protect- 
ed inside  the  skull. 

13.  The  Skeleton  of  each  Upper  Limb   contains  thirty 
bones  and  is  attached  to  the  trunk  by  the  shoulder-girdle. 

14.  The  Shoulder- Girdle  presents  on  each  side  a  collar- 
bone or  clavicle,  in  front  (u,  Fig.  3,  and  c,  Fig.  5),  and  a 
shoulder-blade  or  scapula   (/",  Fig.  5),  behind.     The  collar- 
bone and  shoulder-blade  unite  near  the  shoulder-joint. 

15.  The  Bones  of  the   Arm  and   Hand    (Fig.  3)   are: 
(i)  the  arm-bone,  or  humerus,  t,  which  reaches  from  the 
shoulder  to  the  elbow;  (2)  two  forearm-bones  lying  side 
by  side  between  the  elbow  and   the  wrist;  the  one  on 
the  thumb-side  is  the  radius,  g,  and  that  on  the  little- 
finger  side    the   ulna,  f;    (3)  twenty-seven  hand-bones. 


13.  How  many  bones  in  the  forelimb?      How  is  it  attached  to  the 
trunk  ? 

14.  What  bone  forms  the  front  part  of  the  shoulder-girdle  ?     Be- 
hind ?    Where  do  these  bones  unite  ? 

15.  Name   the   bones   of   the   arm.       Give   position    of  humerus. 
Radius.     Ulna.     Carpal  bones.     Metacarpal.     Phalanges. 


BONES  OP   TffE  LEG  AND  FOOT.  21 

Eight  of  the  hand-bones  are  small  and  lie  close  to  the 
wrist- joint:  they  are  the  carpal  bones,  h.  Five,  the  meta- 
carpal  bones,  i,  lie  in  the  palm  of  the  hand;  fourteen,  the 
phalanges,  k,  are  placed,  three  in  each  finger  and  two  in 
the  thumb. 

16.  The  Skeleton  of  the  Leg  and  Foot  contains,  like  that 
of  the  arm  and  hand,  thirty  bones,  and  is  attached  to  the 
side  of  the  sacrum  by  the  hip-bone. 

17.  The  Hip-Bones  (s,  Fig.  3),  one  on  each  side,  meet  in 
front  and  form,  .with  the  sacrum,  a  bony  ring  enclosing 
the  lower  part  of  the  cavity  of  the  abdomen  or  belly. 
This  ring  is  named  the  pelvis. 

18.  The  Bones  of  the  Leg  and  Foot  are:   (i)  the  thigh- 
bone,  or  femur,  r,  reaching  from  the  hip-joint  to  the  knee: 
it  is  the  longest  bone  in  the  body;  (2)  the  tibia  or  shin- 
bone,  I,  and  fibula,  m,  running  side  by  side  from  knee  to 
ankle-joint;  (3)  the  knee-pan  or  patella,  q,  in  front  of  the 
knee-joint;  (4)  twenty-seven  foot-bones. 

Seven  of  the  foot-bones,  named  tarsal  bones,  n,  lie  below 
the  ankle-joint  and  support  the  heel;  five  metatarsal  bones, 
o,  follow  these;  and  fourteen  phalanges, p,  are  found  in 
the  toes,  two  in  the  great  toe  and  three  in  each  of  the 
others. 

16.  How  many  bones  in  the  leg  ?     How  attached  to  the  sacrum  ? 

17.  Describe  the  hip-bones. 

1 8.  Name  the  leg-bones.    State  position  of  femur.    Tibia.     Fibula. 
Patella.     Tarsal  bones.     Metatarsal  bones.     Phalanges 


22  THE  BONY  SKELETON. 

TABLE  OF  THE  SKELETON. 

THE  BONY  SKELETON:    206  bones. 

HEAD,  NECK,  AND  TRUNK:   80  bones. 
Skull :  29  bones. 

Brain-case,  8  bones,  namely: 

Occipital  bone,  at  back  of  head I 

Frontal  bone,  in  forehead I 

Parietal  bones,  on  top  and  sides  of  head 2 

Temporal  bones,  in  the  temples 2 

Sphenoid  bone,  on  floor  and  sides  of  brain-box I 

Ethmoid  bone,  between  top  of  nose  and  brain  case I 

—  8 
Face-bones,  14,  namely: 

Lower  jaw-bone I 

Vomer,  between  the  nostrils I 

Upper  jaw-bones 2 

Palate-bones,  supporting  part  of  the  roof  of  the  mouth. ...   2 
Malar  bones,   supporting   the   cheek   below  and  outside 

the  eye 2 

Lachrymal  bones,  between  nose  and  eye-socket 2 

Nasal  bones,  on  roof  and  sides  of  nose 2 

Turbinate  bones,  inside  the  nose 2 

—  14 
Ear-bones,  6,  three  on  each  side,  within  the  ear,  namely  : 

Malleus,  or  hammer-bone I 

Incus,  or  anvil-bone I 

Stapes,  or  stirrup-bone  I 

3X2'=      6 
Hyoid  bone,  to  which  the  root  of  the  tongue  is  attached I 

29 
Vertebral  Column:  26  bones,  namely: 

Cervical  (neck)  vertebrae 7 

Dorsal  vertebras,  at  back  of  thorax 12 

Lumbar  (loin)  vertebrae 5 

Sacrum i 

Coccyx i 

—    26 

Bibs :  24  bones,  on  each  side  twelve 24 

Sternum  (breast-bone) i 

80 


THE  BONY  SKELETON.  2$ 

LIMBS  AND  THE  BONES  UNITING  THEM  TO  THE  TRUNK:  126  bones. 
Shoulder-girdle :  4  bones,  on  each  side  two,  namely : 

Clavicle,  or  collar-bone. . .    I 

Scapula,  or  shoulder-blade I 

2X2  =  4 
Arms :  60  bones,  on  each  side  thirty,  namely : 

Humerus I 

Ulna i 

Radius I 

Carpal  or  wrist  bones 8 

Metacarpal  bones 5 

Phalanges 14 

30  X  2  =  60 

Hip-bones  :  on  each  side  one , ,    2 

Legs:  60  bones,  on  each  side  thirty,  namely: 

Femur,  or  thigh-bone I 

Patella,  or  knee-pan I 

Tibia,  or  shin-bone   I 

Fibula,  or  "  small  bone  of  the  leg" I 

Tarsal  (ankle  and  heel)  bones 7 

Metatarsal  bones , 5 

Phalanges 14 

30  X  2  ==  60 
126 


CHAPTER    III. 

THE  STRUCTURE,  COMPOSITION,  AND  HYGIENE  OF  THE 
BONY  SKELETON. 

1.  The  Parts  of  the  Humerus. — Though  bones  differ  in 
shape  and  size,  we  may  get  a  pretty  good  idea  of  the  way 
they  are  all  built  by  studying  the  humerus,  Fig.  7.    This 
presents  a  central  rounded  portion,  or   shaft,  bearing  at 
each  end    an  enlargement,   the  articular  extremity.     The 
shaft  lies  between   the  dotted  lines  x  and  z.     One  use  of 
these  large  ends  is  to  give  more  room  for  the  fastening 
on  of  muscles. 

2.  Internal  Structure. — If  the  humerus  be  sawed  in  two 
lengthwise  (Fig.  8)  we  find  that  its  shaft  is  hollow;  the 
space  is   the   marrow  cavity,  a,  and  during   life   is   filled 
with  a  kind  of  fat.     We  also  see  that  there  are  two  kinds 
of  bony  substance;  one  is  hard  and  close,  the  other  loose 
and  spongy.     The  hard  bone,  b,  lies  on  the  outside,  and 
is  thick  in  the  shaft;  it  forms  only  a  thin   layer   in   the 
extremities,  which  are  filled  with  spongy  bone,  c.      The 
large  marrow-cavity  does  not  extend  into  the  extremi- 
ties. 

3.  Why  Bones  are  Hollow. — All  bones  either  contain  a 
marrow-cavity  or  are  filled  up  with  loose  spongy  tissue. 

1.  Describe  the  humerus  as  viewed  on  its   outside.     For  what  are 
its  large  ends  useful  ? 

2.  What  would  we  find  inside  the  shaft  ?     The  extremities  ? 

3.  What  do  all  bones  contain  ?  Why  are   they  not  filled  with  hard 
bone  ?     Why  are  the  iron  pillars  used  in  building  made  hollow  ? 


Cpl 


FIG.  7. 


FIG. 


FIG.  7.— The  right  humerus,  seen  from  the  front. 

FIG.  8.—  The  humerus  cut  open,     a,  marrow-cavity  ;  b,  hard  bone  ;  c,  spongy 
bone  ;  </,  cartilage. 


26  NOURISHMENT  OF  BONE. 

If  they  were  of  hard  bony  substance  throughout,  they 
would  be  either  very  heavy  and  unnecessarily  strong,  or 
else  too  slender  to  give  surface  enough  for  the  attach- 
ment of  muscles  and  other  organs.  A  given  quantity 
of  material  if  arranged  in  the  form  of  a  tube  will  bear  a 
much  greater  weight  than  if  it  were  made  into  a  solid 
.rod  of  the  same  length  as  the  tube.  For  this  reason, 
iron  pillars  used  in  buildings  to  support  ceilings  and 
floors,  are  hollow.  To  cast  them  solid  would  make  them 
much  heavier  without  great  increase  of  strength. 

4.  How  Bones  are  Nourished. — When  the  humerus  is  in 
the  body,  it  is  closely  surrounded  by  a  connective-tissue 
membrane,   the  periosteum.      This   membrane   is   full    of 
blood  which  nourishes  the  bone  by  means  of  innumer- 
able   little    channels    passing    into    and    branching    all 
through  it.     These   channels   are   too  small  to   be  seen 
without  a  microscope,  but  even   the  most  close-grained 
part  of  every  bone  is  full  of  them.     As  long  as  the  hume- 
rus  is  growing  thicker,  the  periosteum   is  making  new 
bone  on  its  inner  side.     If  this  membrane  is  peeled  off, 
the  bone  dies.     The  parts  of  the  articular  extremities 
(Q>,    7V,    Cpl,   Fig.   7)  which   meet    other  bones  at  the 
shoulder  and  elbow-joints  are  covered  by  cartilage  instead 
of  periosteum. 

5.  The  Chemical  Composition  of  Bone. — The  dried  bone 
of  a  man  in  middle  life,  consists  of  two  parts  of  mineral  to 
one  part  of  animal  matter.  The  minerals  give  the  bone  its 
hardness  and  stiffness;  they  may  be  obtained  separate 

4.  With  what  is  the  humerus  surrounded  ?     How  does  the  perios- 
teum nourish  the  bone  ?     What  happens  if  it  be  peeled  off?     Where 
is  cartilage  found  instead  of  periosteum  ? 

5.  Of  what  does  the  dried  bone  of  a  middle  aged  man  consist? 


COMPOSITION   OF  BONE.  2/ 

by  thoroughly  burning  a  bone.  The  animal  matter  may 
be  obtained  by  soaking  a  bone  for  a  few  days  in  an  acid 
which  dissolves  away  the  minerals. 

The  mineral  matter  by  itself  has  still  the  form  of  the 
bone,  but  is  very  brittle.  The  animal  matter  by  itself 
also  has  the  form  of  the  bone,  but  is  soft  and  easily  bent. 
The  two  mixed  together,  as  they  are  in  the  skeleton, 
make  our  bones  hard  enough  to  support  the  rest  of  the 
body,  and  tough  enough  not  to  be  easily  broken.  The 
animal  matter  also  makes  the  bones  tolerably  flexible 
and  elastic:  some  savages  make  their  bows  from  the  ribs 
of  large  animals. 

In  childhood  the  animal  matter,  and  in  old  age  the 
mineral  matter,  of  bone  is  more  abundaht  than  in  middle 
life.  Therefore  the  bones  of  an  old  person  are  brittle 
and  easily  broken,  while  those  of  a  child  often  bend 
when  the  bones  of  an  adult  would  break. 

6.  Gelatin. — When  a  bone  is  boiled  in  water  for  several 
hours,  most  of  its  animal  matter  is  turned  into  gelatin, 
and  dissolved  in  the  water.  Gelatin  is  a  useful  food; 
most  of  that  which  we  buy  for  making  jelly  is  made  from 
bones.  For  soup  we  use  bones  as  well  as  meat,  and  by 
long  boiling  extract  the  gelatin  from  them.  In  a  piece 
of  meat  as  ordinarily  cooked  most  of  the  gelatin  remains 
in  the  bones,  which  are  therefore  useful  for  soup  and 
should  not  be  thrown  away. 


What  is  the  use  of  the  minerals  ?  How  may  they  be  obtained  sepa- 
rate? How  the  animal  matter?  Characters  of  mineral  matter?  Of 
the  animal  ?  Use  of  having  both  in  a  bone  ?  At  what  time  of  life  is 
the  animal  matter  most  abundant  ?  Why  are  an  old  person's  bones 
easily  broken  ? 

6.   How  may  we  get  gelatin  from  a  bone  ?    Why  are  bones  left 
from  a  piece  of  meat  useful  in  making  soup  ? 


28  HYGIENE    OF  BONES. 

7.  Hygiene  of  the  Bony  Skeleton. — Except  hair  and  teeth, 
bones  are  the  parts  of  the  dead  body  which  most  resist 
decay.  Nevertheless  living  bone  is  readily  altered  in 
shape,  especially  in  young  persons,  by  continued  or  fre- 
quently repeated  pressure  or  strain.  This  is  well  illus- 
trated by  the  curious  forms  which  some  nations  give  to 
their  skulls  (Fig.  9)  by  tying  boards  or  bandages  on  the 
heads  of  their  children. 


FIG.  9.— Skull  of  a  child  of  the  tribe  of  Chinook  Indians  (inhabiting  tne  neigh- 
borhood of  the  Columbia  River),  distorted  by  tight  bandaging  so  as  to  assume  the 
shape  considered  elegant  and  fashionable  by  the  tribe. 

8.  Why  Children  should  have  their  Feet  Supported  and 
should  Sit  Straight . — The  bones  of  a  child  being  rich  in  the 
softer  animal  matter  are  tolerably  flexible,  and  may  be 
readily  made  to  grow  out  of  shape.  Therefore  children 
should  never  be  kept  sitting  on  a  bench  so  high  that  the 
feet  are  not  supported.  If  this  precaution  be  neglected 
the  thigh-bones  become  bent  over  the  edge  of  the  seat 
by  the  weight  of  the  rest  of  the  limb  and  may  be  made 
crooked  for  life. 

7.  What  parts  of  the  dead  body  decay  most  slowly  ?     How  may 
living  bone  be  altered  in  form  ?     Illustrate. 

8.  Why  should    the  feet  of  children   be   supported   when   sitting? 
Why  is  it  important  to  sit  straight  ?     Why   should   children   not  be 
encouraged  to  walk  too  soon  ? 


THE  INSTEP.  29 

For  the  same  reason  it  is  important  to  sit  square  and 
straight  at  the  table  when  writing  or  drawing,  and  with 
the  shoulders  level:  otherwise  the  spinal  column  may 
become  curved  to  one  side. 

Young  children  should  not  be  encouraged  to  walk  too 
early,  lest  they  grow  bow-legged,  their  leg-bones  not 
being  stiff  enough  to  bear  the  weight  of  the  upper  part 
of  the  body. 

9.  Usefulness  of  the  Arch  of  the  Instep. — The  bones  of  the 
foot  (Fig.  10)  are  arranged  to  make  a  springy  arch  which 

Ta 

Cl      C?     XT        I^^^V     BfH 


-JT 

FIG.  10.-  The  skeleton  of  the  foot.  Ca,  the  heel-bone;  C7,  C7/,  C&,  N,  some  of 
the  tarsal  bones;  Os,  the  front  end  of  the  metatarsal  bones;  7/»,  the  surface  which 
makes  the  ankle-joint  with  the  tibia  and  fibula,  and  bears  the  weight  of  the  body 
in  standing  and  walking;  Mi,  metatarsal  bone  of  the  great  toe. 

rests  on  the  ground  by  the  heel-bone,  Ca,  behind,  and  by 
the  front  ends,  Os,  of  the  metatarsal  bones  in  front.  On 
the  crown  of  the  arch  is  the  surface,  Ta,  where  the  foot 
joins  the  leg  at  the  ankle-joint.  At  this  joint  the  weight 
of  the  body  is  borne.  The  many  small  bones  in  the  arch 
glide  over  one  another  a  little  when  the  crown  of  the 
arch  is  pressed  upon;  but  spring  back  into  place  when 
the  pressure  is  removed.  This  elastic  arch  of  the  foot 

9.  Describe  the  construction  of  the  instep.  Why  is  k  arched  and 
elastic  ?  To  what  may  it  be  compared  ?  How  may  we  learn  some- 
thing of  the  jarring  saved  us  by  the  instep  ?  Illustrate  the  usefulness 
of  a  well  arched  instep  in  prolonged  walking. 


3O  HIGH-HEELED  BOOTS. 

lessens  the  jarring  which  would  be  transmitted  to  the 
spinal  column,  and  thence  to  all  the  rest  of  the  body, 
were  the  foot  flat  or  rigid.  A  well-arched  instep  is 
therefore  rightly  considered  beautiful;  it  makes  the  step 
easier  and  more  elastic. 

We  may  compare  it  to  a  carriage-spring,  which  gives 
a  gentle  sway  to  the  vehicle  and  prevents  sudden  jolting. 
How  much  jarring  the  instep  saves  us,  may  be  readily 
learned  by  walking  across  a  room  on  the  heels.  For  a 
steady,  even,  long-continued  tramp,  like  that  of  a  police- 
man, a  foot  well-arched  under  the  instep  is  of  great  im- 
portance: it  not  only  saves  the  upper  parts  of  the  body 
from  injury,  but  much  diminishes  the  fatigue  of  walking. 
Men  who  desire  to  join  the  police  force  but  who  are 
"flat-footed,"  are  rejected;  experience  having  proved 
that  such  persons  cannot  walk  the  daily  "  rounds." 

10.  Why  High-heeled  Boots  are  Hurtful.— When  we 
walk  on  the  heels,  we  are  jarred  at  each  step  because  the 
arch  of  the  instep  is  not  used  as  a  spring.  If  we  walk  on 
the  toes,  this  is  not  the  case,  as  the  elastic  front  half  of 
the  foot  is  brought  into  action.  But  walking  or  running 
on  the  toes  is  fatiguing  because  it  demands  extra  muscu- 
lar effort.  Boots  with  high  heels  lead  practically  to  walk- 
ing on  the  toes.  The  sole  of  the  boot  forms  such  a 
slope,  high  behind  and  low  in  front,  that  the  whole  foot 
slides  forward  on  it,  and  the  heel  has  no  place  on  which 
it  can  bear  firmly  and  take  its  share  of  the  work.  The 
arch  of  the  instep  is  made  useless,  and  the  toes  slip  along 


10.  Why  are  we  not  as  much  jarred  when  we  walk  on  our  toes  as 
if  we  walk  on  our  heels?  Why  is  walking  on  the  toes  fatiguing? 
What  are  the  consequences  of  wearing  high-heeled  boots  ?  Of  boots 
with  pointed  toes  ? 


NARROW-TOED  SOOTS.  31 

until  they  are  squeezed  into  the  toe  of  the  boot;  and  on 
them  all  the  weight  of  the  body  is  there  carried.  The 
so-called  "  French  heel,"  placed  right  under  the  arch  of 
the  instep,  makes  that  piece  of  Nature's  mechanism  per- 
fectly useless. 

The  results  are  an  awkward,  ungraceful  gait;  and  un- 
due fatigue,  leading  to  omission  of  proper  healthy  exer- 
cise, to  the  loss  of  many  innocent  pleasures,  and  often  to 


FIG.  ii. — A,  natural  form  of  the  sole  of  the  foot;  B,  the  same  with  the  outline  of 
an  ordinary  fashionable  boot;  C,  Z>,  feet  which  have  been  made  to  grow  out  of  form 
by  wearing  such  a  boot. 

neglect  of  duties  whose  performance  necessitates  walk- 
ing- 
Continued  wearing  of  narrow-toed  boots,  especially  if 
they  have  also  high  heels,  leads  to  permanent  distortion 
of  the  foot.  Its  front  part  being  forced  into  the  toe  of 
the  boot  by  the  weight  of  the  body,  the  toes  are  pushed 
out  of  place,  frequently  pressed  over  one  another 
(Fig.  n),  and  made  useless;  while  corns  and  bunions  are 


32  TIGHT  LACING, 

developed,  making  the  walk  still  more  painful  and  less 
graceful. 

11.  The  Evils  of  Tight  Lacing  can  only  be  properly  un- 
derstood after  we  have  studied  the  use  and  working  of  the 
heart  and  lungs  (Chap.  XVI.).  With  our  hands  we  can 
press  in  our  lower  ribs  and  narrow  the  chest-cavity;  but 


FIG.  i2.— Skeleton  of  the  chest  of  a  woman,  twenty-three  years  of  age,  deformed 
by  tight  lacing.     Compare  with  the  natural  skeleton,  Fig.  5. 

as  soon  as  we  cease  the  pressure,  the  ribs  spring  back 
to  their  place.  If,  however,  a  tight  corset  be  worn  for 
weeks  or  months,  the  ribs  gradually  yield  to  it  and 
change  their  shape.  The  result  is  a  deformed  chest- 
skeleton  (Fig.  12).  The  lower  ribs  press  on  the  liver, 

ii.   How  does  tight  lacing  alter  the  ribs  ?     What  organs  are  injured 
in  consequence  ? 


BONE S  33 

injuring  it;  and  the  bottom  of  the  chest-cavity  is  so  nar- 
rowed that  the  heart  and  lungs  are  cramped  for  room. 

12.  What  should  be  Done  when  a  Bone  is  Broken. — When 
a  bone  is  broken,  it  is  said  to  be  fractured.     The  muscles 
on  each  side  of  the  break  are  very  apt  to  pull  the  pieces 
of  the  bone  out  of  place.     Therefore  the  broken  bone 
needs  to  be  set  into  place,  and  then  held  by  splints  and 
bandages  so  that  the  ends  be  kept  together  until  they 
unite.     To  set  a  broken  bone,  often  needs  great  skill  and 
a   thorough    knowledge   of   anatomy.     A    medical  man 
should  be  summoned  without  delay,  as  the  parts  around 
the    fracture    usually   swell   very   rapidly,    making   the 
exact  position  of  the  break  hard  to  find  out,  and  the  re- 
placement of  the  pieces  of  the  bone  more  difficult.    Until 
skilled  aid  arrives,  the  sufferer  should  be  kept  as  quiet 
as  possible:  cloths  dipped  in  cold  water  and  frequently 
renewed  may  be  applied  to  keep  down  swelling  and  in- 
flammation. 

13.  How  a  Broken  Bone  is  Knit  together  again. — A 
watery    liquid    first    collects   between    and    around    the 
broken  ends.     This  gradually  thickens,  becoming  jelly- 
like,  and  then  of  the  hardness  of  gristle,  though  it  does 
not    become    actual    cartilage.      It   is   chiefly    made    by 
the   periosteum,  which   becomes  very  active  where  the 
bone  is  broken,  and  makes  this  uniting  material  in  such 
abundance  that  it  forms  quite  a  thick   ring  all   round 
the  fracture.     This  ring,  named  the  callus,  is  afterwards 

12.  What  is  a  fracture  ?    Why  does  a  broken  bone  require  to  be 
set  ?    Why  should  a  doctor  be  summoned  at  once  ?     What  should  be 
done  until  he  arrives  ? 

13.  What  first  happens  when    Nature   begins  to  repair  a  broken 
bone?     Next?     What  makes  this  first  uniting  material  ?     What  is  the 
callus  ?     Its  use  ?    What  finally  becomes  of   it  ?    What  takes  place 
inside  the  callus? 


34  THE   CALLUS. 

hardened  by  lime  being  deposited  in  it.  It  forms  a  sort 
of  natural  splint,  and  strengthens  the  bone  until  the 
ends  have  firmly  grown  together.  Then  it  is  slowly 
absorbed,  and  after  a  few  months  hardly  a  trace  of 
it  is  left.  The  callus  ir»ay  be  compared  to  the  metal 
band  which  is  used  to  hold  together  the  two  parts  of 
a  broken  umbrella-handle.  Inside  the  callus,  new  bone 
slowly  forms  in  the  gristly  layers  between  the  broken 
ends,  and  unites  them.  The  surgeon  usually  removes 
his  artificial  splints  when  the  callus  has  become  well 
developed. 


CHAPTER   IV. 
THE  ORGANS  OF  MOVEMENT  :   MUSCLES  AND  JOINTS. 

1.  Articulations. — Wherever  two  bones  meet  in  the  body 
an  articulation  is  formed.   In  some  articulations  the  bones 
are  fixed  immovably  together,  as  in  the  sutures  of  the  skull, 
(p.  18);  in  others,  to  enable  us  to  move,  the  ends  of  the 
bones  are  so  shaped  and  so  fastened  together  that  one 
can  slide  over  the  other.     Articulations  of  this  kind  are 
called  joints.     Joints  may  be  compared  to  hinges  between 
bones:  examples  are  found  between  the  lower  jaw-bone 
and  the  rest  of  the  skull;  at  shoulder,  elbow,  wrist,  hip, 
knee,  ankle;  and  between  the  bones  of  the  fingers  and  toes. 

2.  The  Movements  of  the  Body  are  brought  about  by 
soft  red  organs  named  muscles.    The  lean  of  meat  is  mus- 
cle, so  every  one  knows  what  dead  muscle  is  like.  Living 
muscle  has  the  power  of  shortening,  or  contracting,  with 
great  force.     When  a  muscle  contracts  it  pulls  its  ends 
together  and  swells  out  in  the  middle;  in  other  words, 
//  becomes  shorter  and  thicker.     If  you  watch  the  front  of 
your  forearm  while  you  forcibly  bend  your  wrist,  you 
can    observe,   through   the  skin,  the  muscles   becoming 
shorter  and  thicker.     Nearly  always  the  two  ends  of  a 

1.  What  is  an  articulation  ?     Of  what  kind  of  articulation  are  the 
sutures  of  the  skull  examples  ?     What  is  a  joint?     Name  some  joints, 

2.  What  is   the  use  of  muscles  ?     What  is  dead  muscle  like  ?    What 
power  has  living  muscle  ?     How  does  it  change  its  shape  in  contract- 
ing ?     Illustrate.     To  what  are  the  ends  of  a  muscle  usually  fixed? 
What  results  when  a  muscle  contracts  ? 


30  HIP-JOINT.       * 

muscle  are  attached  to  separate  bones,  between  which 
a  joint  is  placed;  and  when  the  muscle  contracts  it  pro- 
duces movement  at  the  joint.  The  joints  and  muscles 
are  the  chief  organs  of  movement. 

3.   Joints. — As  an    example    of   a  joint   we  may  take 
that  at  the  hip  (Fig.  13). 


FIG.  13. — The  hip-joint,  sawed  through  its  middle.  The  rounded  head  of  the 
thigh-bone  is  seen  to  fit  into  the  cup  or  socket  of  the  hip-bone.  «,  cartilage  lin- 
ing socket;  £,  cartilage  covering  end  of  femur;  c,  c,  capsular  ligament;  LT,  round 
ligament. 

On  the  outer  side  of  the  hip-bone  (s,  Fig.  3)  is  a  cup- 
like  hollow  which  receives  the  round  upper  end  of  the 
thigh-bone.  Lining  the  cup  is  a  thin  layer  of  cartilage, 
and  covering  the  end  of  the  thigh-bone  is  another.  The 
cartilage  is  extremely  smooth  and  is  kept  moist  by  a  few 
drops  of  joint-oil,  or  synovial  liquid,  so  that  the  end  of  the 


3.  Describe    the  hip-joint, 
vial  fluid?     The  ligaments  ? 


What  use  is  the  cartilage  ?     The  syno- 


BALL-AND-SOCKET  f  OIN  TS.— HINGE-JOINTS.         37 

\ 

femur  rolls  very  easily  in  the  hollow,  or  socket.  The  carti- 
lage forms  a  yielding  cushion  which  hinders  the  bones 
from  scratching  or  chipping  one  another. 

To  keep  the  bones  in  place  and  prevent  too  free  move- 
ment, strong  bands  of  connective  tissue,  called  ligaments, 
unite  them,  being  fixed  above  to  the  hip-bone  and  below 
to  the  femur.  Many  powerful  muscles  also  pass  from  one 
bone  to  the  other,  and  keep  them  pressed  close  together. 

4.  Ball-and-Socket   Joints. — A    joint   like   that   at   the 
hip,  where  the  round  end  of  one  bone  fits  into  a  cavity 
in  which  it  can  roll  in  any  direction,  is  called  a  ball-and- 
socket  joint.       It    allows    more  free   movement  than  any 
other  kind.     At  the  shoulder  there  is  another  ball-and- 
socket  joint. 

5.  Hinge-Joints  — In  hinge-joints  the  ends  of  the  bones 
are  not  evenly  rounded  on  all   sides,  but   one   bone   has 
projecting  ridges  which  slide  in  grooves   on   the   other. 
The  result  is  that  the  only  movements  possible  are  to  and 
fro,  or  in  one  direction  and  back  again,  like  a  door  on  its 
hinges. 

The  knee  is  a  hinge-joint:  it  can  only  be  bent  and 
straightened;  or,  as  physiologists  say,  flexed  &\\&  extended. 
Between  the  phalanges  of  the  fingers  there  are  other 
hinge-joints. 

6.  Pivot-Joints. — In  pivot-joints  one  bone  rolls  round 
another. 

A  good  example  is  the  joint  which  permits  us  to  turn 
the  head  from  side  to  side. 

The   uppermost  vertebra  (Fig.  14),  which  carries   the 

4.  What  is  a  ball-and-socket  joint  ? 

5.  Describe  a  hinge-joint.      Examples. 

6.  What  are  pivot-joints  ?     Describe  the  atlas.     What   is   the   odon- 


38  PI  VO  T-JOIN  TS. 

skull,  has  been  fancifully  named  the  atlas  vertebra,  after 
the  fabled  giant  of  antiquity  who  was  believed  to  bear 
the  heavens  on  his  shoulders.  It  is  ringlike  in  form  and 
the  space  which  it  surrounds  is  separated  by  a  ligament, 
Z,  into  a  smaller  front  and  larger  back  division.  .  In  the 
larger  division  the  spinal  cord  lies.  Into  the  smaller  pro- 
jects a  bony  peg  (D,  Figs.  14  and  15),  called  from  its 
shape  the  toothlike  or  odontoid  process,  which  springs  from 


Aa    Fas 


D 


Pai 


FIG.  14. 


FIG.  15. 


FIG.  14.— The  atlas  vertebra  see i  from  above.     FIG.  15.—  The  axis  vertebra, 
Z/,  the  ligament  which  divides  tie  space  surrounded   by  the  atlas  into  a 'back 
portion,  containing  the  spinal  cord;  and  a  front  portion,  containing  the  odontoid 
process,  Z>,  of  the  axis,  round  which  the  atlas  rolls  when  we  turn  the  head  to  either 
side. 

the  second  or  axis  vertebra.  Knobs  on  the  under  side  of 
the  skull  fit  into  the  hollows  (Fas,  Fig.  14)  on  the  atlas: 
when  we  turn  the  face  to  right  or  left  the  atlas,  carrying 
the  skull  with  it,  rolls  around  the  odontoid  process. 

Another  kind  of  pivot-joint  is  found  in  the  forearm. 
Lay  the  hand  and  forearm  flat  on  a  table,  palm  upwards. 
Without  moving  the  shoulder-joint  at  all,  it  will  be  easy 


toid  process  ?  What  happens  at  the  joint  between  atlas  and  axis 
when  we  turn  the  face  to  one  side  ?  Where  is  there  another  kind  of 
pivot  joint?  What  is  the  position  of  radius  and  ulna  when  the  palm 
of  the  hand  is  turned  up  ?  When  turned  down  ? 


EXPLANATION  OF  PLATE  II. 

A  view  of  the  muscles  situated  on  the  front  surface  of  the  body, 
seen  in  their  natural  position.  It  must  be  understood  that  beneath 
these  muscles  many  others  are  situated,  which  cannot  be  represented 
in  the  figure. 

Muscles  of  the  Face,  Head,  and  Neck: 

1.  Muscle  of  the  Forehead.    This,  together  with  a  muscle  at  the  back  of  the 

head,  has  the  power  of  moving  the  scalp. 

2.  Muscle  that  closes  the  Eyelids.     The  muscle  that  raises  the  upper  eyelid 

so  as  to  open  the  eye,  is  situated  within  the  orbit,  and  consequently 
cannot  be  seen  in  this  figure. 

3.  4,  5.  Muscles  that  raise  the  Upper  Lip  and  angle  of  the  Mouth. 

6,  7.  Muscles  that  depress  the  Lower  Lip  and  angle  of  the  Mouth.  By  the 
action  of  the  muscles  which  raise  the  upper  lip,  and  those  that  depress 
the  lower  lip,  the  lips  are  separated. 

8.  Muscle  that  draws  the  Lips  together,  so  as  to  close  the  Mouth. 

9.  Muscle  of  the  Temple  (Temporal  Muscle). 

10.  Masseter  Muscle.    9  and  10  are  the  two  chief  muscles  of  mastication,  for 

when  they  contract,  the  movable  lower  jaw  is  elevated,  so  as  to  crush 
the  food  between  the  teeth  in  the  upper  and  lower  jaws. 

11.  Muscle  that  compresses  the  Nostril.    Close  to  its  outer  side  is  a  small 

muscle  that  dilates  the  nostril. 

12.  Muscle  that  wrinkles  the  Skin  of  the  Neck,  and  assists  in  depressing  the 

lower  jaw. 

13.  Muscle  that  assists  in  steadying  the  Head,  and  also  in  moving  it  from  side 

to  side. 

14.  Muscles  that  depress  the  Windpipe  and  Organ  of  Voice.    The  muscles 

that  elevate  the  same  parts  are  placed  beneath  the  lower  jaw,  and  can- 
not be  seen  in  the  figure. 

Muscles  that  connect  the  upper  extremity  to  the  trunk.  Portions 
of  four  of  these  muscles  are  represented  in  the  figure,  viz. : 

15.  Muscle  that  elevates  the  Shoulder.    Trapezius  Muscle. 

17.  Great  Muscle  of  the  Chest,  which  draws  the  Arm  in  front  of  the  Chest 

(Great  Pectoral  Muscle). 

18.  Broad  Muscle  of  the  Back,  which  draws  the  Arm  downwards  across  the 

back  of  the  Body  (Latissimus  Dorsi). 

19.  Serrated  Muscle  extends  between  the  Ribs  and  Shoulder-blade,  and  draws 

the  shoulder  forwards  and  rotates  it,  a  movement  which  takes  place  in 
the  elevation  of  the  arm  above  the  head  (Serratus  magnus). 


At  the  lower  part  of  the  trunk,  on  each  side,  may  be  seen  the  large 
muscle  which,  from  the  oblique  direction  of  its  fibres,  is  called, 

20.  Outer  Oblique  Muscle  of  the  Abdomen. 

Several  muscles  lie  beneath  it.     The  outline  of  one  of  these, 

21.  Straight  Muscle  of  the  Abdomen,  may  be  seen  beneath  the  expanded 

tendon  of  insertion  of  the  oblique  muscle.  These  abdominal  muscles, 
by  their  contraction,  possess  the  power  of  compressing  the  contents  of 
the  abdomen. 

Muscles  of  the  upper  extremity: 
16.  Muscle  that  elevates  the  Arm  (Deltoid  Muscle). 

22.  Biceps  or  Two-headed  Muscle  (see  also  page  41). 

23.  Anterior  Muscle  of  the  Arm.    This  and  the  Biceps  are  for  the  purpose  of 

bending  the  Fore -Arm. 

24.  Triceps,  or  Three-headed  Muscle.    This  counteracts  the  last  two  muscles, 

for  it  extends  the  Fore-arm. 

25.  Muscles  that  bend  the  Wrist  and  Fingers,  and  pronate  the  Fore-arm  and 

Hand— that  is,  turn  the  Hand  with  the  palm  downwards.  They  are 
called  the  Flexor  and  Pronator  Muscles. 

26.  Muscles  that  extend  the  Wrist  and  Fingers,  and  supinate  the  Fore-arm 

and  Hand— that  is,  turn  the  Hand  with  its  palm  upwards.  They  are 
called  the  Extensor  and  Supinator  Muscles. 

27.  Muscles  that  constitute  the  ball  of  the  Thumb.    They  move  it  in  different 

directions. 

28.  Muscles  that  move  the  Little  Finger. 

Muscles  which  connect  the  lower  extremity  to  the  pelvic  bone. 
Several  are  represented  in  the  figure. 

29.  Muscle  usually  stated  to  have  the  power  of  crossing  one  Leg  over  the 

other,  hence  called  the  Tailor's  Muscle,  or  Sartorius;  its  real  action  is 
to  assist  in  bending  the  knee. 

30.  Muscles  that  draw  the  Thighs  together  (Adductor  Muscles). 

31.  Muscles  that  extend  or  straighten  the   Leg   (Extensor   Muscles).    The 

muscles  that  bend  the  leg  are  placed  on  the  back  of  the  thigh,  so  that 
they  cannot  be  seen  in  the  figure. 

Muscles  of  the  leg  and  foot : 

32.  Muscles  that  bend  the  Foot  upon  the  Leg,  and  extend  the  Toes. 

33.  Muscles  that  raise  the  Heel— these  form  the  prominence  of  the  calf  of  tho 

Leg. 

34.  Muscles  that  turn  the  Foot  outwards. 

35.  A  band  of  membrane  which  retains  in  position  the  tendons  which  pass 

from  the  leg  to  the  foot. 

36.  A  short  muscle  which  extends  the  Toes. 

The  muscles  which  turn  the  foot  inwards,  so  as  to  counteract  the 
last  named  muscles,  lie  beneath  the  great  muscles  of  the  calf,  which 
consequently  conceal  them.  The  foot  possesses  numerous  muscles, 
which  act  upon  the  toes,  so  as  to  move  them  about  in  various  direc- 
tions. These  are  principally  placed  on  the  sole  of  the  foot,  so  that 
they  cannot  be  seen  in  the  figure.  Only  one  muscle,  36,  which  assists 
in  extending  the  toes,  is  placed  on  the  back  of  the  foot. 


27 


PLATE   1I.-THE  SUPERFICIAL  MUSCLES  OF  THE  EROXT  OF  THE  BODY- 


MUSCLES. 


39 


to  turn  the  hand,  palm  downwards.  This  is  done  (Fig.  16) 
by  rolling  the  lower  end  of  the  radius,  which  carries  the 
hand,  around  the  ulna.  When  the  palm  is  upward  the 
radius  and  ulna  lie  side  by  side  as  shown  at  A\  while  it 
is  being  turned  downward,  the  lower  end  of  the  radius 
rolls  around  the  ulna  and  at 
last  crosses  it  to  get  on  its  •*' 
inner  side,  as  shown  at  B. 


7.  The  Muscles  of  the  human 
body  are  more  than  five  hun- 
dred in  number.  They  vary  in 
size  from  tiny  ones  inside  the 
ear,  not  half  an  inch  long,  to 
that  (29,Plate  II.)  which  passes 
from  the  pelvis  to  the  tibia  and 
is  eighteen  inches  or  more  in 
length.  All  muscles  have  the 
power  of  shortening  and  thus 
of  pulling  other  parts  (usu- 
ally bones)  to  which  their 
ends  may  be  attached.  After  F,G°i6.-Bones  of  the  forearm 

111  j  j      a°d   hand.      A,    the    palm    turned 

a  muscle   has   shortened   and     forwards  or  upwards  <**//««/«»«), 

.  .  1-11  and  the    radius  and    ulna  parallel; 

done     Its     WOrk,     It     lengthens      B,  the  palm   turned  downwards  or 

.  backwards  (pronation),  and  the  ra- 

agam,  or  relaxes.     In  addition     dius  crossing  the  ulna. 

to   their   chief    function    of    moving    the    body,  muscles 

clothe    the    skeleton    and    make    the    form     round    and 

shapely;    they  aid  in  enclosing  cavities,   as  the  mouth 

and  abdomen;  and  they  help  to  hold  bones  together  at 

joints. 


7.   How  many  muscles  in  the  body  ?     Their  size?    On  what  do  our 
movements  depend  ?    What  other  functions  have  muscles  ? 


MUSCLES  OF   THE  ARM. 


FIG.  17.— The  muscles  on  the 
back  of  the  hand,  forearm,  and 
lower  half  of  the  arm,  as  ex- 
posed on  dissecting  away  the 
skin. 


8.  The  Parts  of  a  Muscle.— In 
its  most  common  form,  a  muscle 
consists    of   a    red    soft    middle 
part,  called  its  belly,  which  tapers 
towards  each  end  and  passes  into 
very  tough  white  cords  named 
tendons  or  sinews,     The  tendons 
may  be  compared  to  ropes,  tying 
the  working  part  of  the  muscle, 
namely   its  belly,  to  the  bones 
which  the  muscle  has  to  move. 
The  hard   cord-like   tendons  of 
the    muscles    which    bend    the 
fingers,can  easily  be  felt  through 
the  skin  in  front  of  the  wrist. 

9.  The  Muscles    of   the    Arm, 
some    of    which    are    shown    in 
Fig.    17,    may   be    taken    to    il- 
lustrate   the    structure   and    ar- 
rangement of  nearly  all  muscles. 
We  see  that  some  (8,  n,  12)  pass 
over  the  elbow-joint  from  arm  to 
forearm.     Others  (14,  15,  16,  17, 
18)  start  from  the  ulna  or  radius 
and  pass  over  the  wrist-joint  to 
the  hand.     Near  the  wrist  most 
of  them  end  in  slender  tendons, 
which   are   kept    in  place   by  a 
strong  cross-band  of  connective 
tissue   (++).      The  skin  has  been 
dissected  away  from    the  back 


8.  What  parts  has  a  muscle  ?    Their  uses  ? 
.   Describe  the  course  of  some  of  the  arm-muscles. 


THE  BTCEPS-MUSCLE.  4! 

of   the   middle  finger   to   show  the  ending  of   tendons 
on  it. 

10.  How  we  may  Recognize  the  Working  of  a  Muscle.— 
The  shortening  of  a  muscle,  when  it  is  at  work,  is  suf- 
ficiently shown  by  the  way  it  pulls  the  bones;  as  when 
we  bend  the  elbow-joint  or  the  fingers.  The  thickening 
may  be  seen  and  felt  on  the  biceps-muscle  (Fig.  18),  in 
front  of  the  humerus,  when  the  elbow  is  bent;  or  on  the 
muscles  of  the  ball  of  the  thumb,  when  we  move  the 


FIG.  18. — The  biceps-muscle  and  the  arm-bones,  to  illustrate  how  the  elbow-joint 
is  bent,  when  the  biceps-muscle  contracts  and  becomes  shorter  and  thicker. 

thumb  so  as  to  make  it  touch  the  little  finger.  When  a 
muscle  contracts,  its  belly  becomes  harder.  The  swell- 
ing and  hardening  of  a  contracted  muscle  are  daily  illus- 
trated when  a  school-boy  bends  his  elbow  as  powerfully 
as  he  can  and  then  invites  another  to  feel  his  "  biceps." 
11.  Muscles  not  directly  attached  to  the  Skeleton. — Most 
of  these  surround  openings,  which  they  close  when  they 
contract.  Thus  around  the  mouth-aperture  is  a  ring 

10.  How  may  we  recognize  the  shortening  of  a  working  muscle  ? 
The  thickening  ?     The  hardening  ? 

11.  Give  examples  of  muscles  not  directly  attached  to  bones. 


42          HOW   THE  MUSCLES  ARE   CONTROLLED. 

of  muscle  (orbicularis  en's,  8,  PI.  II.)  which  shuts  the  mouth, 
or  if  more  vigorously  contracted  purses  out  the  lips,  as 
when  a  child  holds  up  its  mouth  to  be  kissed.  A  similar 
ring-like  muscle  (orbicularis  palpebrarum,  2,  PI.  II.)  sur- 
rounds the  opening  between  the  eyelids  and  closes  the 
eyes. 

12.  How  the  Muscles  are  Controlled. — It  is  very  clear 
that  we  could  not  do  what  we  wanted  to  do  if  our  mus- 
cles contracted  at  random:  they  must  be  held  in  control; 
kept  at  rest  when  their  action  is  not  needed,  and  made  to 
work  when  it  is.     If  the  muscles  closing  the  mouth  con- 
tracted when  we  tried  to  put  food  into  it  we  should  be 
in  a  bad  plight.     All  the  muscles  are  directed  and  guided 
in  their  work  by  the  nervous  system  (Chap.  XVIII.).  From 
the  brain  and  spinal  cord  nerves  run  to  them,  governing 
all  and  making  them  work  together  in  harmony  ;    those 
which   straighten   the  elbow-joint  are  not,  for  example, 
permitted   to  pull  when  we  desire  to  bend  it.     In  convul- 
sions the  controlling  nervous  organs  cease  their  guidance; 
the  muscles  contract  in  all  sorts  of  irregular  and  useless 
ways;    and,    often,   since  those  which    produce   exactly 
opposite  movements  contract  at  the  same  moment,  the 
whole  body  is  made  stiff. 

13.  Involuntary  Muscles. — The  muscles  hitherto  con- 
sidered are  all  more  or  less  under  the  control  of  our  will. 
We  can  make  them  contract  or  prevent  their  contraction  as 
we  choose.     They  are  called  the  voluntary  muscles.     There 
are  other  muscles  whose   working  we  cannot   control; 

12.  What  power  must  we  have  over  our  muscles  ?     What  is  the  use 
of  the  nerves  of  the  muscles  ?     In  what  organs  do  they  commence  ? 
How  do  the  muscles  behave  during  a  fit  of  convulsions?     Why? 

13.  What  are  voluntary  muscles?     Involuntary?     Where  found? 
Use? 


INVOLUNTARY  MUSCLES.  43 

they  are  named  involuntary  muscles.  Involuntary  muscles 
are  not  attached  to  the  skeleton  nor  concerned  in  our 
ordinary  movements,  but  lie  in  the  walls  of  hollow 
organs,  as  the  stomach  and  intestine  (Chap.  XI.).  When 
they  contract  they  push  along  the  contents  of  these 
organs. 

14.  As  a  general  rule  all  the  movements  most  necessary 
for  keeping  the  body  alive,  as  those  which  cause  the  blood 


FIG.  19.— The  muscular  coat  of  the  stomach. 

to  flow  to  all  organs  or  food  to  travel  along  the  ali- 
mentary canal,  are  taken  by  Nature  out  of  our  control, 
and  performed  by  involuntary  muscles.  It  is,  however, 
impossible  to  draw  a  sharp  line  between  voluntary 
and  involuntary  muscles.  The  breathing  muscles  are 
partly  subject  to  our  will  :  any  one  can  draw  a  long 
breath  when  he  chooses.  But  in  ordinary  quiet  breath- 
ing, we  are  quite  unconscious  of  the  working  of  these 

14.  What  class  of  movements  is  not  subject  to  our  will  ?  Illustrate. 
What  is  said  concerning  the  breathing  muscles?  Give  instances  in 
which  other  voluntary  muscles  contract  against  our  will. 


44  STANDING. 

muscles;  and  even  when  we  pay  heed  to  it,  our  control 
is  limited:  no  one  can  hold  his  breath  long  enough  to 
suffocate  himself.  Any  one  of  the  voluntary  muscles 
may  be  thrown  into  activity,  independently  of  or  even 
against  the  will,  as  we  see  in  the  "fidgets"  of  nervous- 
ness. When  we  call  any  muscle  voluntary,  we  mean  that 
it  may  be  controlled  by  the  will,  but  not  that  it  neces- 
sarily always  is  so. 

15.  Standing. — There  are   two  reasons  why  a  young 
infant  cannot  stand:  the  first   is  that   its  skeleton   is  not 
firm  enough  to  bear  its  weight;  the  second  is  that  it  can- 
not guide  and  manage  its  muscles.     After  the  bones  are 
strong  enough  a  child  has  still  to  learn  to  stand.     We 
all   at  last  become  by  practice  able   to   do  so  without 
thinking  about  it;  but  standing  always  demands  that  a 
great  many  muscles  shall  be  at  work,  and   be  guided  by 
the  brain.     The  part  the  brain   takes,  although  we  usu- 
ally know  nothing  about  it,  is  shown  by  the  fall  which 
results   from  a  violent  knock  on   the   head.     This  may 
break  no  bone  and  injure  no  muscle,  and  yet  the  man  who 
has  received  it  falls  stunned  and  helpless  to  the  ground. 
His  brain   has   been  so  shaken  that  it  ceases  for  a  time 
to  do  its  work,  and  the  consequence  is  that  the  muscles, 
released  from  control,  cease  to  do  their  work;  so  until 
the  brain  recovers,  the  man  cannot  stand. 

16.  How  our  Brains  come  to  Control  the  Muscles  without 
our  being  Conscious  of  it  — A  child  learning  to  stand  has 
to  take  a  great  deal  of  trouble;  it  has  to  think  about 
what  it  is  doing  all  the  time.    After  a  while,  it  gives  less 

15.  Why  cannot  an  infant  stand?     How  is  the  brain  concerned  in 
standing?     In  what  way  is  this  fact  shown  ? 

16.  Give  an  example  of  an  action   once  performed  with    trouble 


UNCONSCIOUS  MUSCULAR  ACTION.  45 

and  less  thought  to  the  proper  action  of  the  muscles  of 
standing;  and  at  last  its  brain  does  the  work  without  any 
thinking  about  it  at  all.  The  child  then  stands,  as  it 
breathes,  almost  or  quite  unconsciously.  This  is  a  very 
curious  and  a  very  important  fact.  It  is  but  one  example 
of  many,  showing  that  actions  of  our  muscles  which  once 
cost  thought  and  effort,  come  at  last  to  be  done  with- 
out either.  Practice  not  only  "  makes  perfect,"  it  also 
makes  easy  that  which  before  was  difficult.  The  trouble 
with  which  we  learn  to  ride  or  swim,  or  strike  the  proper 
keys  of  a  piano,  thinking  about  every  necessary  move- 
ment, and  the  ease  with  which  we  come  at  last  to  do 
these  things,  are  other  examples  of  the  same  fact.  When 
any  muscular  action  which  was  at  first  performed  with 
difficulty  and  by  "  willing"  to  do  it,  comes  to  be  per- 
formed almost  unconsciously,  without  our  will,  we  say  a 
habit  has  been  formed.  When  the  brain  and  muscles 
have  been  trained  to  work  together  in  this  unconscious 
way,  it  is  as  hard  or  harder  to  break  the  habit  than  it 
was  to  acquire  it.  A  practised  rider  would  have  to  take 
a  good  deal  of  trouble  to  fall  off  his  horse  under  ordi- 
nary circumstances,  or  a  good  swimmer  to  drown  himself. 
This  tendency  of  the  brain  and  muscles  to  do  at  last 
without  the  will,  or  against  it,  that  which  they  have 
often  done  before  in  consequence  of  the  will,  is  of  the 
greatest  importance.  It  is  the  physiological  reason  for 
acquiring  good  habits  and  avoiding  bad.  The  more 
often  we  do  anything,  the  easier  it  is  to  do  it  again,  and 
the  harder  to  avoid  doing  it. 

which  at  last  comes  to  be  done  unconsciously.  Other  illustrations. 
What  is  a  habit?  How  do  habits  come  to  control  us?  What  is  the 
physiological  reason  for  forming  good  habits  and  avoiding  bad? 


STANDING. 


17.  The  Muscles  concerned  in  Standing.  —  In  consequence 
of  the  flexibility  of  the  ankle-,  knee-,  and  hip-joints,  a 
dead  body  cannot  be  balanced  on 
its  feet,  as  a  marble  statue  may  be. 
When  a  man  stands,  the  joints  would 
bend,  were  they  not  braced  and  held 
firm  by  muscles.  When  we  stand,  mus- 
cles (Fig.  20,  i)  in  front  of  the  ankle- 
joint,  and  others  (/)  behind  it,  con- 
tracting at  the  same  time,  keep  that 
joint  from  yielding.  In  the  same  way, 
j  _C/J  muscles  (2)  in  front  of  the  knee-  and 

hip-joints,  are  opposed  by  others  (//) 
behind  them,  and  when  we  stand,  both 
contract  and  keep  those  joints  rigid. 
The  muscles  (///)  which  run  from  the 
pelvis  to  the  back  of  the  head,  in  like 
manner  pull  against  others  (3  and  4) 
which  run  from  the  pelvis  to  the  lower 
[  end  of  the  breast-bone,  and  from  the 
lull  I  i  uppcr  end  of  the  breast-bone  to  the 
front  part  of  the  skull;  their  bal- 
anced contraction  keeps  the  head  erect. 
If  one  falls  asleep  while  sitting  or 
illustrating  the  mus-  standing,  the  chin  drops,  because  the 
muscles  holding  the  head  upright  have 
relaxed  their  vigilance,  and  its  front' 
bhoedjr0iresc[.igidandthe  part  is  heavier  than  its  back.  Since 
the  degree  to  which  each  muscle  contracts  when  we 

17.  How  do  the  muscles  enable  us  to  stand  ?  Why  does  the  head 
fall  forward  if  one  goes  to  sleep  standing?  Why  does  it  take  time  to 
learn  to  stand  ? 


FIG.  20.  —  Diagram 

lustrating  the  mus- 

cles    (drawn   in    thick 


A   FEW  HINTS  FOR    TEACHERS.  47 

stand,  must  be  exactly  equal  to  the  contraction  of  its 

antagonist  on  the  opposite  side  of  the  joint,  we  easily 
see  why  it  takes  some  time  to  learn  to  stand. 


APPENDIX  TO  CHAPTER   IV. 

Many  of  the  facts  described  in  this  chapter  can  be  exhibited  to  a 
class  with  little  trouble  or  expense. 

1.  The  sutures  may  be  well  seen  on  the  skull  of  a  rabbit  or  sheep. 
All  that  is  necessary  is  to  boil  it  thoroughly  and  then  pick  the  bones 
clean,  and  wash  out  the  brain. 

2.  The  structure  of  joints  is  easily  exhibited  on  the  fresh  foot  of  a 
sheep  or  calf.     On  cutting  open  the  joints  the  tough  ligaments  around 
them  will  be  seen.     The  slippery  synovial  liquid  covering  the  inside 
of  the  joint  can  be  felt  by  the  finger.     The  smooth  gristle  will  be 
found  to  form  a  layer  over  the  bones  within  the  joint.     A  thin  slice 
of  it  may  be  readily  cut  off  with  a  knife,  and  its  translucency,  flexi- 
bility, and  springiness  exhibited. 

3.  An  example  of  a  ball-and-socket  joint  may  be  easily  obtained  by 
cleaning  the  thigh-  and  hip-bones  of  a  rabbit  or  chicken. 

4.  For  a  good  example  of  a  hinge-joint  the  most  easily  available 
object  is  the  skull  of  a  dead  cat.      In  this  animal  the  lower  jaw  forms 
a  perfect  hinge-joint  with  the  rest  of  the  skull. 

5.  The  pivot- joint  between  atlas  and  axis  can  be  demonstrated  on 
the  bones  of  a  sheep's  head  and  neck,   after  the  piece  of  meat  has 
done  its  duty  at   table.     For  this  purpose  buy  mutton.     The  odon- 
toid process  of  a  lamb  is  apt  to  separate. 

6.  The  form  and  structure  of  muscles  can  readily  be  exhibited  on 
the  hind  leg  of  a  frog.      Place  the  animal  for  a  few  minutes  in  a  cov- 
ered jar  containing  a  pint  of  water  to  which  has  been  added  a  tea- 
spoonful  of  ether.     When  the  creature  has  become  quite  unconscious 
take  it  out,  cut  off  its  head,  and  run  a  stout  pin  down  its  back-bone 
to  destroy  the  spinal  cord.      In  this  way  all  chance  of  giving  pain  is 
avoided.     Then  divide  the  skin  at  the  top  of  each  leg  and  pull  it  off. 
Point  out  especially  the  muscles  between  knee-  and  ankle-joints,  and 
their  long  white  tendons,  many  of  them  running  to  the  toes. 

The  leg  of  a  chicken  or  turkey  also  affords  an  excellent  object  for 
examining  tendons.  The  bellies  of  most  of  the  muscles  which  move 
the  toes  lie  in  the  part  of  the  leg  known  as  the  "drumstick."  Their 
tendons  run  down  the  shank,  and,  if  the  skin  be  dissected  off  this, 
are  readily  found.  Pulling  some  of  the  tendons  bends  the  toes,  pull- 
ing others  straightens  them;  just  as  when  they  were  pulled  during 
life  by  the  contracting  bellies  of  the  muscles  in  the  drumstick. 

7.  The  nerve  of  a  muscle  can  be  easily  shown  on  the  calf-muscle 
of  a  frog's  leg.     Cut  the  tendon  (tendo  AchiHis)  which  attaches  this 
muscle  to  the  heel.     Then  turn  the  muscle  up,  so  as  to  expose  its 
under  side.     Its  nerve  will  be  seen,  as  a  slender  white  thread,  enter- 
ing its  deeper  side  a  little  way  below  the  knee. 


CHAPTER   V. 

CARE  OF  THE  JOINTS  AND   MUSCLES. 

1.  Dislocations  and  Sprains. — When  we  slip  or  stumble, 
some  joint  has  to  share  with  the  bones  the  strain  of  our 
effort  to  recover  our  balance;  or  the  weight  of  the  body 
if  we  fall.     Accidents  to  the  joints  are  accordingly  quite 
frequent,  and  it  is  important  to  know  how  to  manage 
them  until  medical  aid  can  be  obtained.     A  sprain  is  an 
injury  in  which  the  ends  of  the  bones  remain  in  place 
but  the  ligaments  are  stretched  or  twisted  or  torn.     In 
a  dislocation,  the   ligaments   of   the   joint  are   torn,  and 
the  ends  of  the  bones  forced  out  of  their  proper  posi- 
tions. 

2.  How  to  Treat  a  Sprain. — The  most  important  point  is 
to  give  the  joint  complete  rest.     The  injured  ligaments 
become  swollen  and  painful,  and  movement  makes  them 
worse.     In  the  case  of  sprains  of  the  finger  and  wrist  the 
inflammation  is  often  slight,  and  can  be  controlled  by 
wrapping  the  joint  in  a  moderately  tight  bandage  for  a 
few  days,  and  keeping  the  arm  in  a  sling  so  as  to  hinder  it 
from  being  used.    If  the  pain  and  swelling  are  great,  the 
bandage  should  be  kept  wet  with  cold  water.     Sprains 

1.  Why  are  accidents  to  the  joints  frequent?     What  is  a  sprain? 
A  dislocation  ? 

2.  What  does  a  sprained  joint  most  require  ?     Why  ?     How  may  a 
slight  sprain  of  a  finger  or  wrist  be  treated?     What  should  be  done 
when  a  knee  or  ankle  is  sprained  ? 


DISLOCATIONS.— GOUT.  49 

of  the  knee  and  ankle  joints  are  apt  to  be  more  serious, 
and  if  neglected  or  unwisely  managed  may  lead  to  per- 
manent lameness.  In  such  accidents  it  is  best  to  send  at 
once  for  a  surgeon  ;  until  he  arrives,  if  the  pain  is  great, 
apply  cloths  wrung  out  of  hot  water. 

3.  What  to  do  in  Case  of  a  Dislocation. — The  ligaments 
and   soft   parts  around   dislocated  joints  swell  rapidly, 
and  make  it  not  only  difficult  to  find  out  in  what  direc- 
tion  the  bones  have  been  displaced,  but,  after  finding 
this,  difficult   to  replace  them.     When   a  dislocation  is 
suspected,  get  skilled  advice  as  soon  as  possible;  mean- 
time keep  the  joint  at  rest.     More  harm   than  good  is 
almost  certain  to  be  done  by  the  twisting  and  pulling 
and  pushing  of  persons  ignorant  of  anatomy. 

A  dislocated  finger  may,  however,  be  in  most  cases 
safely  reduced — that  is,  have  the  bones  put  into  place— by 
almost  any  one.  What  is  needed  is  a  strong  pull,  com- 
bined with  pressure  near  the  joint.  The  reduction  of  a 
dislocated  thumb  should  never  be  attempted  except  by  a 
surgeon. 

4.  Gout  is  a  disease  in  which  some  joints,  usually  of 
the  toes  or   fingers,  become  red,  swollen,  painful,   and 
very  tender.     Gritty  matter  also  accumulates  in  them, 
making  the  cartilage  rough  and  the  joint  stiff.     In  nine 
cases  out   of  ten  gout  is  due  to  indolent  and  luxurious 
habits,  too  little  exercise,  too  much  animal  food,  and, 
above  all,  indulgence  in  alcoholic  drinks.     The    disease, 
like  many  others  produced   by  alcohol,  tends  to  be  in- 
herited, and  so  some  persons  suffer  from  gout  through 

3.  Why  should  a  surgeon  be  called  at  once  in  case  of  most  disloca- 
tions ?     How  may  a  dislocated  finger  be  usually  reduced  ? 

4.  What  is  gout  ?     To  what  often  due  ?     What  is  said  concerning 
hereditary  gout  ?     Is  gout  ever  fatal  ? 


50  RHEUMATISM. 

the  fault  of  a  parent;  overwork  may  bring  on  an  attack 
in  such.  Even  those  born  with  a  gouty  tendency  may, 
however,  usually  escape  if  careful  in  their  habits. 

Gout  is  not  merely  painful  but  dangerous.  It  often 
attacks  the  heart,  causing  sudden  death. 

5.  Rheumatism  is  a  name  given  to  different  diseases. 
In  rheumatism  of  the  joints,  or  rheumatic  fever,  the  liga- 
ments of  most  of  the  joints  of  the  body  are  swollen  and 
inflamed.  The  inflammation  often  attacks  also  the 
membrane  which  covers  the  heart,  or  the  valves  inside  it 
(Chap.  XIII.),  sometimes  leaving  incurable  heart-disease 
when  the  rheumatism  itself  has  gone. 

The  most  common  cause  of  rheumatic  fever  is  pro- 
longed exposure  of  the  skin,  especially  if  it  be  hot  and 
perspiring,  to  chilling  while  the  body  is  at  rest.  There- 
fore, when  warm,  especially  avoid  sitting  in  a  draught. 
Exposure  to  cold  air  when  exercising,  or  a  plunge 
into  cold  water  for  a  few  minutes'  swim,  will  not  cause 
the  disease;  but  sitting  still  in  a  current  of  air  or  in 
wet  clothes,  or  sleeping  in  damp  sheets,  is  apt  to  do  so. 

It  is  also  well  to  know  that  rheumatic  fever  is  more 
common,  and  more  apt  to  cause  heart-disease,  in  young 
persons  than  in  old. 

Chronic  or  permanent  rheumatism  may  attack  either  the 
joints  or  the  muscles.  It  makes  the  joints  stiff,  painful, 
and  finally  useless.  The  most  frequent  form  of  chronic 
rheumatism  of  the  muscles  is  lumbago,  in  which  the  lum- 
bar muscles  in  the  lower  part  of  the  back  are  affected. 
Exposure  to  cold  and  wet  is.  its  most  common  cause;  but 

5.  How  are  the  joints  affected  in  rheumatic  fever?  The  heart? 
How  is  this  disease  commonly  produced  ?  Why  specially  dangerous 
to  the  young?  What  parts  does  chronic  rheumatism  attack?  Its 
effects  on  the  joints  ?  What  is  lumbago  ?  Usual  causes  ? 


HYGIENE   OF  MUSCLES.  5 1 

the  tendency  to  acquire  it  is  much  promoted  by  indul- 
gence in  alcoholic  drinks. 

6.  The   Importance   of  keeping   our    Muscles   in  Good 
Working  Condition. — Man's  mind  is  more  than  his  body, 
but  the  mind  turns  its  thoughts  into  deeds  by  means  of 
the  voluntary  muscles.     The  better  their  state,  the  more 
promptly  do  they  obey  its  commands;  while  a  feeble  or 
sluggish  set  of  muscles  will  often  bring  to  naught  the 
best-laid  plans  of  the  mind. 

Mind  without  the  power  of  directing  movement,  would 
be  a  source  rather  of  pain  than  pleasure.  Muscles  un- 
guided  by  mind  would  make  but  a  piece  of  machinery,  as 
incapable  of  enjoyment  as  a  steam-engine.  Between 
these  extremes,  there  lies  a  combination  of  vigorous  well- 
trained  brain  and  healthy  active  muscle,  which  is  the 
highest  condition  of  bodily  welfare. 

7.  Hygiene  of  the  Muscles. — Every  time  a  muscle  is 
worked,  some  of  its  substance  is  used  up  and  turned  into 
waste  matters.     Nourishment  must  therefore  be  brought 
to  the  muscle,  that  new  substance  be  formed   instead  of 
that  destroyed;    and   the  waste    matters,   which  would 
poison  the  muscle  if  they  were  allowed  to  collect,  must 
be  removed.     Both  of  these  things  are  done  by  the  blood: 
and  the  blood  must  be  kept  in  good  condition  by  nour- 
ishing food  and  pure  air,  if  the  muscles  are  to  be  healthy 
and  vigorous.    No  article  of  dress  should  press  tightly  on 
any  muscle;  if  it  does  it  will  hinder  a  free  flow  of  blood 
in  it  and  interfere  with  its  proper  nourishment. 

6.  Why  would  our  minds   be  of  little   use  without  our  muscles? 
What  is  the  highest  condition  of  bodily  welfare  ? 

7.  What  happens  to  some  of  its  substance  when   a  muscle  is  used? 
What  follows  from  this?     What  part  does  the  blood  play  in  keeping 
the  muscles   in   health  ?     What  are  necessary  to   keep  the  blood   in 
proper  condition  ?     How  may  a  tight  garment  injure  our  muscles  ? 


52  EXERCISE. 

8.  Exercise. — After  good  air  and  food  the  most   im- 
portant   condition  for   keeping    the  muscles  healthy   is 
that  they  be  used  regularly,  or  exercised.     A  muscle  left  in 
idleness  dwindles  in  size  and  becomes  worse  in  quality: 
instead  of  being  hard,  firm,  and  ready  to  contract,  it  be- 
comes soft,  flabby,  and  feeble.     This  fact   is  well  shown 
in  the  muscles  of  an  arm  or  leg  which  has  been  kept  mo- 
tionless for  a  few  weeks  while  a  broken  bone  is  healing. 
When  the  bandages  and  splints  are  taken  off,  the  mus- 
cles are  nearly  powerless,  and  much  smaller  than  those 
of    the    opposite   limb,  which  have    been   kept    in   use. 
Only  by  careful  continued  exercise,  do  they  regain  their 
former  size  and  strength.     The  opposite  fact,  that  mus- 
cles when  used  grow  bigger  and  become  more  powerful, 
is  illustrated  by  the  huge  "  brawny"  arm  of  a  blacksmith. 

9.  Too  Much  Exercise  is  as  Harmful  as  too  Little. — When 
a  muscle  is  at  work,  it  is  used  up  faster  than  new  muscle- 
substance  is  made;  also,  waste  substances  are  produced 
faster  than  the  blood  can  carry  them  off.     After  a  time, 
this  causes  a  feeling  of  being  tired,  which  is  Nature's 
signal  that  it  is  time  to  rest.     To  exercise  until  we  are  a 
little  tired,  does   no  harm;  indeed,  rather  benefits   than 
hurts  the  muscles,  if  followed  by  proper  repose.     During 
a  time  of  rest  following  moderate  work,  more  blood  than 
usual  flows  to  the  muscle,  conveying  more  nourishment 
than  is  needed  for  its  repair;  and  so  it  grows  larger  and 

8.  After  good  food  and  air  what  is  next  in  importance  for  our  mus- 
cles?    How  does  continued  idleness  affect  them  ?    Illustrate.    Give  an 
example  of  the  improvement  of  muscles  by  exercise. 

9.  Why  do  we  feel  tired  after  hard  muscular  work  ?     What  happens 
when  we  rest  our  muscles  after  moderate  fatigue  ?     How  does  repeated 
overwork  affect  the  muscles  ?     The  body  in  general  ?     What  is  neces- 
sary for  healthy  muscles?     How  is  this  illustrated  by  the  heart  ?     The 
breathing  muscles  ? 


EXERCISE.  53 

stronger.  Frequent  exercise  carried  on  to  the  point  of 
great  fatigue,  leads  to  wasting  away  and  weakness  of  the 
muscles  as  surely  as  does  continued  idleness.  It  also 
enfeebles  the  whole  body  and  makes  it  more  liable  to 
many  diseases. 

Action  and  repose  in  turn,  and  neither  in  excess,  are  the 
conditions  necessary  for  healthy  muscles.  In  those  whose 
action  we  cannot  control  by  the  will,  we  find  this  illus- 
trated. The  heart  is  a  muscle  which  contracts  seventy 
times  or  more  every  minute,  in  its  work  of  pumping  the 
blood  all  over  the  body.  Yet  the  heart  beats  on  year 
after  year  and  feels  no  fatigue.  The  secret  of  this  is  that 
after  every  contraction  it  rests  before  it  makes  the  next 
one.  The  muscles  which  cause  the  movements  of  breath- 
ing, teach  us  the  same  lesson.  If  they  stopped  their  work 
for  five  minutes,  we  should  die  for  want  of  fresh  air  in 
our  lungs.  After  each  breath  we  draw,  they  take  their 
rest,  and  so  keep  at  work  fifteen  or  sixteen  times  a  min- 
ute all  life  long. 

10.  The  Proper  Amount  of  Exercise  is  not  the  same 
for  all  persons.  A  strong  healthy  boy  or  girl  runs  about 
until  pretty  thoroughly  tired,  then  goes  home,  eats  a 
good  supper,  sleeps  soundly,  and  wakes  in  the  morning 
feeling  all  the  better  for  the  exercise.  One  who  is  deli- 
cate, should  always  rest  as  soon  as  the  least  fatigue  is  felt. 
Being  delicate  means,  in  most  cases,  that  the  organs  of 
the  body,  the  muscles  along  with  the  rest,  only  nourish 
themselves  slowly;  short  exercise  and  long  rest  are  there- 
fore necessary.  If  a  person  who  is  not  strong  becomes 

10.  When  should  a  delicate  person  stop  exercising  ?  Why  ?  What 
is  the  result  if  a  delicate  person  overexerts  himself?  How  may 
healthful  games  be  made  injurious  ?  What  is  about  sufficient  regu- 
lar exercise  for  a  healthy  adult  of  sedentary  habits  ? 


54  EXERCISE. 

greatly  tired,  he  has  little  appetite,  sleeps  badly,  and  next 
morning  still  feels  weary.  His  exercise,  being  more  than 
his  body  is  suited  to  bear,  has  done  him  harm.  Many 
children  (not  to  mention  grown-up  folks,  who  might  be 
supposed  to  know  better)  run  about  in  the  excitement 
of  some  game,  without  realizing  the  fatigue,  until  after 
they  have  greatly  overworked  and  injured  their  muscles. 
A  walk  of  from  six  to  seven  miles  daily  is  about  the 
proper  amount  of  exercise  for  a  grown  person  of  ordi- 
nary strength,  whose  business  is  such  as  to  keep  him 
sitting  most  of  the  day  and  who  is  not  able  to  take  any 
other  outdoor  exercise.  Horseback-riding  is  better  for 
those  who  can  afford  it  (p.  57). 

11.  When  to  Exercise. — Severe  muscular  work  causes, 
as  we  have  learned,  great  muscular  waste,  and  demands 
an  abundant  supply  of  nourishment  for  the  repair  of  the 
muscles.     For  this  reason,  violent  exercise  should  not  be 
taken  after  a  long  fast.     Strong  vigorous  young  people 
may  walk  several  miles  before  breakfast  and  not  suffer  in 
consequence,  but  others  had  better  wait  until  after  eating, 
before  undertaking  any  great  muscular  exertion.    Neither 
should  exercise  be  taken  immediately  after  a  meal.     At 
that  time,  a  great  deal  of  blood  is  needed  in  the  stomach 
and  intestines  to  help  in  digesting  the  food  (Chap.  XI.); 
and  it  cannot  be  drained  off  to  supply  the  muscles  as  it  is 
during  exercise,  without  risk  of  an  attack  of  indigestion. 

12.  Exercise  should  be  Regular. — When  we  work  our 
voluntary  muscles,  we  give  the  heart  and  lungs  more  work 
to  do.    The  heart  has  to  pump  more  blood  to  the  muscles, 

11.  Why  is  it  not  wise  to  undertake  hard  muscular  work  when  fast- 
ing?   Just  after  eating  ? 

12.  How  does  muscular  exercise  affect  the  heart  and  lungs?    What 


EXERCISE.  55 

l 

and  the  lungs  have  to  get  rid  of  the  extra  waste  matters 
(Chap.  XV.).  You  know  that  after  running  fifty  yards 
at  full  speed,  you  find  yourself  breathing  faster  and  your 
heart  beating  quicker.  If  you  are  used  to  such  racing, 
you  soon  get  your  breath  again,  and  your  heart  quiets 
down;  for  those  organs,  having  been  gradually  trained  to 
work  just  as  your  muscles  need  their  help,  do  it  easily  and 
comfortably.  But  if  a  boy  who  is  not  used  to  running 
starts  off  on  a  fast  race,  he  soon  has  to  stop,  panting  for 
breath,  feeling  his  overstrained  heart  thumping  in  his 
chest,  and  probably  with  "a  stitch  in  his  side."  Exercise 
leading  to  such  results  does  harm.  A  healthy  boy  usually 
gets  all  right  again  in  half  an  hour  or  so;  but  quite  often 
fatal  disease  of  the  heart  has  been  caused,  even  in  strong 
young  persons,  by  prolonged  violent  exercise  to  which 
they  were  not  accustomed.  Girls  have  in  several  cases 
died  in  consequence  of  excessive  exercise  with  the  skip- 
ping-rope. Running  to  catch  a  train  has  often  produced 
serious  and  lasting  heart-disease  in  those  who  were  weak 
or  no  longer  young,  and  who  were  unused  to  such  mus- 
cular exertion. 

An  occasional  long  walk  at  a  moderate  rate,  or  leisurely 
rowing  a  boat  for  an  hour  or  two,  if  followed  by  a  good 
rest,  will  not  injure  any  one  in  ordinary  fair  health:  those 
whose  pursuits  confine  them  to  a  desk  most  days  are 
usually  benefited  by  such  exercise  once  a  week.  But 
fast  running,  or  foot-ball  playing,  or  rowing  a  race,  should 
never  be  undertaken  by  those  who  have  not  gradually 
educated  their  bodies  to  bear  violent  exercise. 

may  you  notice  after  running?  What  happens  if  a  boy  undertakes 
violent  exercise  without  training?  What  organ  is  apt  to  be  especially 
injured  by  unusual  muscular  exertion  ?  Why  is  it  better  to  miss  a  train 
than  race  to  catch  it  if  you  are  not  used  to  running  ? 


5  EXERCISE. 

13.  Proper  Exercise  Benefits  not  only  the  Muscles  but  tLe 
whole  Body. — Suitable  exercise  makes  the  heart  do  more 
work  in  pumping  blood  over  the  body,  but  not  enough 
extra  work  to  injure  the  heart  itself;  the  consequence  is 
a  better  nourishment  of  all  the  organs.  Such  exercise 
also  makes  us  breathe  faster  and  deeper  and  so  bring 
more  air  into  our  lungs.  If  the  air  be  pure  and  fresh, 
this  also  benefits  all  the  organs.  The  muscles  take  their 
toll  of  the  general  beneficial  results;  but  if  their  work  is 
not  excessive,  a  good  deal  of  the  profit  is  left  for  other 
organs.  The  digestive  organs  are  put  in  better  working 
state,  appetite  is  increased  and  more  food  eaten  and 
used;  the  skin  and  other  organs  concerned  in  getting 
rid  of  wastes,  work  better;  the  brain  is  better  nourished; 
the  mind  clearer;  and  work  which  without  exercise  was 
laborious  and  wearisome  becomes  easy  and  agreeable. 

It  is  on  these  benefits  to  the  body  in  general,  which  re- 
sult from  proper  exercise  of  the  muscles,  that  the  duty  of 
taking  such  exercise  mainly  rests.  It  is  not  a  particu- 
larly lofty  ambition  to  be  strong  enough  to  knock  down 
another  man  in  a  stand-up  fight,  though  there  may  be 
occasions  when  such  muscular  strength  is  very  desirable. 
In  the  long-run,  the  world  is  guided  and  ruled  by  vigor- 
ous minds  more  than  by  muscular  bodies.  Exercise,  in 
promoting  the  general  health  of  the  body,  promotes  men- 
tal vigor;  and  when  pursued  not  for  its  own  sake  or  for 
mere  athletic  glory,  tends  to  quicken  the  intellect,  invig- 
orate the  will,  and  strengthen  character.  Other  things 
being  equal,  the  healthy  man  or  woman  is  the  best  in  all 
the  circumstances  of  life. 

13.  How  does  proper  muscular  exercise  benefit  the  whole  body  ? 
What  is  the  chief  reason  which  makes  it  a  duty  to  take  proper  exercise  ? 


EXERCISE.  57 

14.  Varieties  of   Exercise. — In   walking,  the  muscles 
chiefly  employed  are  those  of  the  lower  limbs  and  trunk; 
the  muscles  of  the  arms  are  hardly  used.     Rowing  and 
riding  are  better,  since  in  them  nearly  all  the  muscles  are 
exercised.     No  one  exercise  employs  in  equal  proportion 
all  the  muscles,  and  gymnasia,  in  which  different  feats  of 
agility  are  practised  so  as  to  call  different  muscles  into 
action  as  may  be  desirable,  have  a  deserved  popularity. 
It  should  be   borne  in  mind,  however,  that  in  the  arms 
delicacy  of  movement  is  more  important  to  many  per- 
sons than  great  strength.     The  fact  that  gymnastics  are 
usually  practised   indoors  is  also  a  great  drawback  to 
their  value.     Out-of-door  exercise  in  good  or  even  mod- 
erate weather,  is  better  than  any  other,  and  every  one  can 
at  least  take  a  walk.     The  daily  "  constitutional  "  is,  how- 
ever, very  apt  to  become  wearisome,  and  exercise  loses 
half  its  value  if  unattended  with  feelings  of  mental  re- 
.laxation  and   pleasure.     Active  games,  for  this  reason, 
have  a  great  value  for  young  and  healthy  persons;  lawn- 
tennis,,  base-ball,  and  cricket  are  all  attended  with  pleas- 
urable excitement,  and  are  excellent  also  as  exercising 
many  muscles. 

15.  We  cannot  profitably  Work  Hard  with,  both  Brain  and 
Muscle. — Few  persons  can  continue  to  put  both  body  and 
mind  to  severe  daily  work  without  risk.     Many  a  college 
student  has  completely  broken  down  his  health  in  the 
attempt.     Every  one  should,  however,  regularly  use  both 

14.  What  muscles  are  left  unexercised  in  walking  ?    Why  are  row- 
ing and  riding  better  exercises  ?     Why  are  gymnasia  useful  ?     What 
is  the  chief  drawback  to  gymnastics  ?    Why  are  active  games  espe- 
cially valuable  ? 

15.  Why  is  it  unwise  for  most  persons  to  attempt  to  excel  in  both 
athletics  and  study  ?    What  should  every  cne  do? 


$8  ACTION  OF  ALCOHOL   ON  MUSCLES. 

mind  and  muscle,  doing  his  work  with  one  and  simply 
exercising  the  other.  Thus  both  are  kept  in  health. 

16.  The  Action  of  Alcoholic  Drinks  on  the  Muscles. — In- 
dulgence in  beers,  wines,  or  spirits  never  does  any  good 
to  the  muscular  system  of  a  healthy  person,  and  often 
does  great  harm.  The  injury  may  be  direct  or  indirect; 
when  indirect  it  is  due  to  weakened  will,  impaired  di- 
gestion, enfeebled  heart,  or  disease  of  organs  whose  func- 
tion it  is  to  carry  waste  matters  away  from  the  body. 
How  alcohol  leads  to  these  consequences  we  shall  Study 
in  following  chapters. 

The  action  of  alcohol  on  the  power  of  the  muscles  has 
often  been  carefully  studied.  Experiments  prove  that 
it  is  less  on  days  in  which  spirits  are  taken  (Chap.  IX.). 

Continued  indulgence  in  alcoholic  drinks  causes  change 
for  the  worse  in  the  structure  of  the  muscles.  The  con- 
nective tissue  and  fat  in  them  become  too  abundant  and 
take  the  place  of  the  proper  muscular  substance.  This 
consequence  is  especially  frequent  in  the  muscular  tissue 
of  the  heart  (p.  162). 

16.  How  may  alcoholic  drinks  indirectly  harm  the  muscular  sys- 
tem? What  has  been  observed  as  to  their  direct  action  on  muscular 
power  ?  What  changes  in  the  structure  of  muscle  are  produced  by 
continued  alcoholic  indulgence  ?  In  what  organ  are  they  most  fre- 
quently observed  ? 


CHAPTER  VI. 

"iHE  SKIN. 

1.  The  Skin  is  the  tough  pliable  membrane  which  sur- 
rounds  and  protects   the  rest  of   the  body.     It   is    not 
tightly  fixed  to  the  parts  beneath  it,  but  can  glide  over 
them  or  be  pinched  up  in  a  fold;  as  you  may  easily  ob- 
serve on  the  back  of  your  hand.     The  loose  tissue  which 
attaches  the  skin  to  parts  under  it  contains  a  good  deal 
of  fat,  except  in  very  thin  people;  thus  the  form  is  made 
rounder  and  more  beautiful  than  it  would  be  if  the  skin 
fitted  close  to  every  bone  or,  muscle  beneath.     This  fat 
also  serves  as  a  soft  padding  or  cushion  protecting  the 
deeper  parts  from  injury  by  blows;  and  it  checks  loss  of 
heat    from    the    internal    organs,  by  forming   a    sort   of 
blanket  around  the  body.     In  old  age  most  of  the  fat  is 
apt  to  disappear;  the  skin  then   falls  into  wrinkles,  be- 
cause it  is  too  loose  to  fit  neatly;  and  extra  clothing  is 
required  to  keep  in  the  heat  of  the  body. 

2.  Structure  of  the  Skin. — The  skin  is  made  of  two  very 
different  layers.     The   inner  layer  is  named  the  dermis, 
and  the  outer  the  epidermis  or  cuticle.     When  your  hand 
or  foot  becomes  blistered  in  consequence  of  some  exer- 

1.  What  is  the  nature  of  the  skin  ?     How  is  it  attached  to  parts  be- 
neath ?     Point  out  some  uses  of  the  fat  under  the  skin.     Why  are  old 
people  wrinkled? 

2.  What  two  layers  compose  the  skin  ?    How  is  a  blister  produced? 


60  DERM  IS  AND  EPIDERMIS. 

cise  to  which  it  is  not  accustomed,  liquid  collects  between 
the  cuticle  and  the  dermis,  causing  the  blister. 

3.  What  we  may  Learn  from  a  Blistered  Hand. — When 
you    open    a    blister,  you    feel    no    pain    when    cutting 
through  its  outer  covering;  but   if  you   touch  the  raw 
surface  beneath,  it  smarts.     This  shows  that  the  epider- 
mis has   little   or   no   feeling,  while   the   dermis   is   very 
sensitive.      You   may  also    obsefve   that  when    you  cut 
through    the   cuticle,  there    is    no    bleeding;    but  if  you 
gently    prick    with    a    pin-point    the    dermis    under  the 
blister,    blood    will   flow.     This  shows   that  the  dermis 
contains  blood  and  the  epidermis  does  not. 

4.  Other  Illustrations  of  the  Difference  between  the  Der- 
mis and  Epidermis. — Without  waiting  for  a  blister,  you 
may  readily  learn  the  facts  described  in  the  preceding 
paragraph.     Take  a  small  needle  threaded  with  fine  silk, 
and,  if   you  are  careful  not  to  go  deep,   you   can   em- 
broider a  pattern  on  your  hand  without  causing  pain  or 
drawing  blood.     But  if  the  point  of  the  needle  enters 
the  dermis,  you  feel  the  prick,  and  a  drop  of   blood    is 
very  likely  to  flow  from  the  wound. 

5.  How  the  Epidermis  is  Shed  and  Renewed. — If  you  have 
ever  seen  an  old  brick  house,  you  may  have  noticed  that  the 
bricks  on  the  outside  of  the  wall  are  worn  away,  crumbly, 
easily  broken,  and  the  mortar  between  them  loose;  while 
the  bricks  and  mortar  which  lie  deeper  in  the  wall  and 
have   not    been    exposed    to  the  weather,  are  perfectly 
sound.     The  epidermis  (Fig.  21)  is  made  up  of  millions 

3.  How  may  we  learn  from  a  blister  which  layer  of  the  skin  is  sen- 
sitive  ?     How  discover  which  contains  blood  ? 

4.  How  may  we  in  another  way  observe  the  same  facts  ? 

5.  What  might  you  notice  on   an   old  brick  house?     How  do   its 
walls  resemble  the  epidermis  ?    Of  what  is  the  epidermis  made  up  ? 


EPIDERMIS. 


of  little  pieces,  called  cells,  joined  together  by  a  sort  of 
glue.     The  cells  may  be  compared  to  the  bricks,  and  the 


*— a 


FIG.  21. — A  thin  slice  of  epidermis,  greatly  magnified,  a,  the  outer  or  horny  layer 
of  the  epidermis,  made  of  old  dry  cells;  £,  the  deeper  moist  layer  of  the  epidermis, 
made  of  living  growing  cells;  </,  the  deepest  row  of  epidermic  cells,  lying  next  the 
dermis;  c,  the  uppermost  layer  of  the  dermis;  (it  is  seen  to  be  elevated  to  form  a 
papilla  in  which  is  a  tuft  of  tubes,/,  g,  containing  blood;)  A,  the  duct  of  a  sweat- 
gland. 

glue  to  the  mortar,  of  a  wall.     Each  cell  is  so  small  that 
a  powerful  microscope  would  be  needed  to  see  one  by 


62  COMPLEXION. 

itself,  but,  cemented  together  in  thousands,  they  make 
up  the  tough  epidermis,  as  we  see  it  covering  a  blister. 
The  cells,  #,  near  the  surface,  exposed  to  the  air  and  to 
wear  and  tear  from  rubbing  against  the  clothes  and 
other  things,  become  different  from  the  deeper  cells,  b. 
The  outside  part  of  the  epidermis  is  in  fact  dead,  and  is 
being  constantly  shed  and  got  rid  of.  Sometimes  many 
cells  come  off  together,  as  seen  in  the  "peeling"  of  the 
skin  after  an  attack  of  measles,  or  in  the  rolls  of  matter 
which  a  rough  towel  rubs  off  after  a  warm  bath.  These 
outer  cells  make  what  is  known  as  the  horny  layer  of  the 
epidermis.  It  may  be  compared  to  a  very  thin  sheet 
of  india-rubber  covering  the  body. 

6.  The  deeper  cells  of  the  epidermis  are  kept  moist 
and   well    nourished  by  a  colorless  liquid   which  exudes 
from  the  blood-vessels,/,^-,  of  the  dermis  beneath  them. 
They  grow  and  divide,  and  thus  make  new  cells,  which  in 
turn  are  pushed  to  the  outside  to  build  the  horny  layer. 
Beneath  a  blister,  some  of  the   deepest  epidermic  cells 
remain  sticking  on  the  dermis.     Being  well  nourished, 
they    multiply    very    fast    and    soon    restore    the    whole 
thickness  of  the  cuticle,  so  that  in  two  or  three  weeks  no 
trace  of  the  blister  remains. 

7.  The  Complexion  is  due  to  the  color  of  the  deepest 
cells  of   the  epidermis.       In   persons  of  blond    or   fair 
complexion,  these  cells  contain  very  little  dark  coloring 

How  is  the  outermost  part  of  the  epidermis  worn  away  and  renewed  ? 
What  does  a  rough  towel  rub  off  the  skin  after  a  bath?  To  what  may 
the  outer  layer  of  the  epidermis  be  compared  ? 

6.  Describe  the  life-history  of  the  deeper  cells  of  the  epidermis. 
How  is  the  epidermis  restored  after  it  has  been  removed  by  a  blister? 

7.  How  does  the  epidermis  of  a  blond  differ  from  that  of  a  bru- 
nette?    How  does  sunlight  affect  the  epidermis?     Why  is  the  scar  of 
a  deep  wound  white  ? 


DERMIS.  63 

matter.  In  those  of  brunette  or  dark  complexion,  this 
pigment  is  more  abundant.  In  negroes  there  is  a  large 
amount  of  it. 

Exposure  to  the  air  and  to  sunlight  increases  the  quan- 
tity of  coloring  matter  in  the  epidermis.  Hence  the 
skin  darkens  or  "  tans."  If  the  whole  thickness  of  the 
epidermis  is  destroyed,  by  a  burn  or  wound,  the  deepest 
cells  of  the  new  epidermis  do  not  usually  form  any  color- 
ing matter;  therefore  scars  remain  white,  even  in  negroes. 

8.  Redness  of  the  Skin  and   blushing  are  due  not  to 
changes  in  the  epidermis,  but  in  the  dermis,  which  be- 
comes  fuller   of   blood.     The    red   blood    is    then    seen 
through  the  epidermis.     Constant  pallor  or  great  white- 
ness of  the  skin,  is  a  sign  that  there  is  not  enough  blood 
flowing  in  the  dermis;  it  is  usually  an  indication  of  dis- 
ease.    Some  persons  are  pale  from  infancy  and  neverthe- 
less healthy;  but  they  are  exceptional. 

9.  The  Dermis  consists  of  a  close  network  of  connec- 
tive tissue,  containing  in  its  meshes  many  nerves,  and 
numerous  tubes  filled   with   blood,  named   blood-vessels. 
It  is  the  nerves  (Chap.  XVIII.)  which   give  it  feeling. 
When  hides  are  tanned,  the  dermis  is  turned  into  leather. 
Its  outer  surface,  next  the  epidermis,  is  not  smooth,  but 
presents  numerous  tiny  projections,  named  papilla.     In 
Fig.  21  is  shown  a  papilla  containing  a  knot   of  blood- 
vessels.    Other  papillae  contain  nerves  instead  of  blood- 
vessels, and  are  concerned  in  the  feeling  of  touch.     On 
the  palm   of   the   hand,  the  papillae  of  the  dermis  are 

8.  What  is  the  cause  of  redness  of  the  skin  ?    Of  pallor  ?     Is  con- 
stant pallor  always  a  sign  of  disease  ? 

9.  Of  what  is  the  dermis  composed  ?     What  are  its  papillae?     What 
do  different  papillae  contain  ?     How  are  the  fine  ridges  and  furrows  of 
the  palm  produced  ?     What  causes  the  deep  lines  of  the  palm  ? 


64  THE  NAILS. 

arranged  in  rows.  The  epidermis  fills  up  the  hollows 
between  those  of  the  same  row,  but  dips  down  be- 
tween neighboring  rows.  In  this  way  the  fine  ridges 
and  furrows  of  the  palm  are  produced.  The  deeper 
grooves  of  the  palm,  from  whose  size  and  course  gyp- 
sies pretend  to  tell  the  fortune,  have  a  different  cause. 
They  mark  lines  where  the  skin  is  most  frequently 
folded  in  the  movements  of  the  hand,  and  where  it  is 
more  tightly  tied  down  to  the  parts  beneath  it. 

10.  Nails  are  made    by  a   great    development  of   the 
horny  layer  of  the  epidermis  on  the  ends  of  the  toes  and 
fingers.     This  layer  at  these  places   becomes  very  thick, 
and  grows  out  beyond  the  rest  of  the  skin  to  form  the 
edge  of  the  nail.     Our  nails  provide  an  armor  to  protect 
the  tips  of  the  tender  fingers  and  toes,  which  are   liable 
to  many  accidents.     This   protective  use  of  the  nail  is 
well  seen  in  the  hoof  of  a  horse  or  cow,  which   is  but  a 
thick  nail.     In  beasts  of  prey,  as  cats  and  lions,  the  nails 
take  the  form  of  claws  and  are  used  in  climbing  and  in 
catching  prey. 

Each  nail  is  nourished  by  thedermis  beneath  it,  and  at 
its  root.  If  it  be  torn  off,  or  be  shed  in  consequence  of  a 
blow,  it  is  reproduced,  provided  the  dermis  also  has  not 
been  seriously  injured. 

11.  Hairs,  long  or  short,  coarse  or  fine,  scanty  or  nu- 
merous, are  found  all   over   the   skin  except  in  a  few 
places,  as  the  palms  of  the  hands  and  the  soles  of  the 

10.  Of  what  are  nails  made  ?     Use  of  the  nails  to  man  ?     What  is  a 
hoof?    A  claw  ?     How  are  nails  nourished?     What  is  necessary  in 
order  that  a  "  cast"  nail  may  be  replaced  ? 

11.  On  what  parts  of  the  skin  are  there  no  hairs  ?     What  is  a  hair  ? 
What  is  the  use  of  its  papilla  ?     What  is  the  follicle  of  a  hair  ?     The 
root  ?    What  are  the  uses  of  hairs  ? 


HAIRS. 


feet.  A  hair  is  a  thread  of  epid 
top  of  a  papilla  of  the  dermis 
bottom  of  a  tiny  pit  in  the  skin. 
On  the  papilla,  new  epidermic 
cells  are  produced  as  long  as 
the  hair  continues  to  grow. 
When  a  hair  is  shed  or  pulled 
out,  a  new  one  grows  in  its 
place  if  the  papilla  has  not 
been  injured.  The  part  of 
a  hair  which  lies  within  its 
pit  or  follicle,  is  known  as  its 
root. 

In  many  of  the  lower  animals, 
hairs  have  an  important  use  as 
clothing.  In  man  the  hair  of 
the  head  may  serve  this  pur- 
pose to  some  extent;  it  also 
aids  in  protecting  the  skull 
from  injury.  The  eyelashes 
keep  dust  from  falling  into  the 
eye;  and  the  fine  hairs  over 
most  of  the  surface  drag  on 
their  roots  when  pushed  and 
aid  in  the  sense  of  touch.  The 
papillae  on  which  the  hairs 
grow,  are  richly  supplied  with 
nerves. 

12.  The  Glands  of  the  Skin.- 
the  body  have  as  their  special 


ermis  which  grows  on  the 
(/,  Fig.  22)  placed  at  the 


FIG.  22. — The  root  of  a  hair,  em- 
bedded in  the  pit  of  the  skin  in 
which  it  grew.  «,  stem  of  the  hair, 
cut  short;  <?,  £,  root  of  the  hair;  c, 
swollen  end  of  the  root  which  fits 
on  the  papilla  of  the  dermis,  *, 
which  nourishes  the  hair;  k,  £, 
openings  of  the  ducts  of  oil-glands. 

-Certain  hollow  organs  of 
duty  the   preparation  of 


12.  What  are  glands?     A  secretion  ?     A  duct?    What  glands  pour 
their  secretion  on  the  skin  ? 


66 


PER SP IRA  TION. 


peculiar  liquids  which  they  pass  out  through  tubes. 
Such  organs  are  called  glands  :  the  liquid  which  a  gland 
collects  or  manufactures,  is  known  as  its  secretion;  and 
the  tube  through  which  the  secretion  is  poured  is  named 
a  duct.  Two  kinds  of  glands  empty  their 
secretion  on  the  skin.  They  are  the 
sweat,  or  sudoriparous,  glands,  and  the  oil, 
or  sebaceous,  glands. 

13.  The  Sweat-Glands  (Fig.  23)  make 
the  perspiration.     They  are  very  slender 
tubes    which    reach    from    the    surface, 
through   epidermis  and  dermis,  to  the 
fatty  tissue  beneath  the  skin.     There  the 
tube  coils  up  into  a  knot.     These  glands 
are    found    all    over   the    skin,  but    not 
equally  distributed.     In  the  palm  of  the 
hand  there  are  nearly  three  thousand  to 
each  square  inch:  on  the  middle  of  the 
back,  where  they  are  fewest,  about  four 
hundred  in  the  same  space.     There  are 
in  all  about  two  and  a  half  millions  of 
sweat-glands. 

14.  The   Perspiration   or  Sweat  is  a 
transparent  colorless  liquid,  consisting 

mainly  of  water.  Anything  tending  to  heat  the  body 
causes  perspiration  to  flow  more  freely,  so  its  amount 
is  very  variable.  On  an  average,  it  is  at  least  two  pounds 
daily.  The  sweat  may  dry  up,  or  evaporate,  as  fast  as  it 

13.  Describe  a  sweat-gland.     What  is  the  number  of  these  glands 
in  a  square  inch  of  the  palm  ?     Of  the  skin  of  the  back?     How  many 
are  there  altogether  in  the  skin  ? 

14.  Describe  the  sweat.     Why  is  it  variable   in  amount?     What  is 
its  average  quantity  ?     What  is  "  insensible"  perspiration  ?     Sensible  ? 


FIG.  23  —A  sweat- 
gland.  «,  horny  lay- 
er of  the  cuticle;  c, 
deeper  layer  of  the 
cuticle;  6,  the  der- 
mis. The  duct  of  the 
gland  is  seen  to  run 
through  the  epider- 
mis and  dermis  and 
end  in  a  coiled  mass 
placed  in  the  fatty 
tissue  beneath  the 
skin. 


OIL-GLANDS.  67 

is  poured  out:  then  it  is  named  insensible  perspiration. 
When  it  is  poured  out  faster  than  it  evaporates,  sweat 
collects  in  drops  on  the  skin,  and  especially  in  regions,  as 
the  forehead,  where  the  glands  are  very  abundant.  It  is 
then  named  sensible  perspiration. 

15.  The  Chief  Use  of  the  Sweat-Glands  is  to  cool  the 
body  when    there   is   danger   of    its    becoming   too   hot. 
Whenever  a  liquid  dries  up  or  evaporates,  it  draws  heat 
from  whatever  it  lies   on.     Your  saliva  is  warmer  than 
the  skin  of  your  finger,  but  if,  after  wetting  your  finger 
with  this  warmer  liquid,  you  expose  it  to  the  air  it  feels 
cool,  because  as  the  moisture  dries  up,  it  takes  heat  from 
the  skin.     Our  bodies  only  work  well  when  they  have  a 
temperature  of  about  98  degrees  of  an  ordinary  or  Fah- 
renheit thermometer.     If  they  get  a  little  hotter  than  this, 
fever  results,  and  many  organs  either  cease  to  work,  or 
work  very  badly.     In  health,  the  sweat-glands  pour  addi- 
tional liquid  on  the  skin  on  a  hot  day,  or  when  we  are 
heated  by  exercise;  and  the  heat  taken  away  in  the  evapo- 
ration of  this  extra  quantity  of  water,  keeps   the   body 
cooled  down  to  its  proper  temperature.     When  the  body 
is  cold  the  sweat-glands  (except  in  disease)  almost  cease 
to  make  perspiration,  and  so  loss  of  heat  is  checked. 

16.  The  Sebaceous  or  Oil  Glands  of  the  skin,  pour  their 
secretion  into  the  sides  of  the  pits  in  which  the  roots  of 
the  hairs  are  contained.     The  openings  of  the  ducts  of  a 
pair  of  sebaceous  glands  are  seen  at  k  in  Fig.  22.     The 

15.  What  is  the  chief  use  of  the  sweat-glands?     Explain.     What  is 
the  proper  temperature  of  the  body  ?     If  it  become  a  little  hotter  what 
results?     When  do   the  sweat-glands  secrete  freelv  ?      When  little? 
Why? 

16.  Where  do  the  sebaceous  glands  pour  their  secretion  ?     What  are 
its  uses?     How  do  the  sebaceous  glands  sometimes  cause  black  spots 
in  the  skin  ? 


68  SUMMAR  Y. 

oily  matter  which  they  produce  is  partly  spread  over  the 
hairs,  and  partly  over  the  general  surface  of  the  skin. 
A  healthy  skin  is  always  a  little  greasy,  except  on  the 
palms  of  the  hands  and  the  soles  of  the  feet,  where  there 
are  no  hairs  and  no  oil-glands.  This  oily  covering  pre- 
vents the  skin  from  absorbing  water  when  the  air  is 
damp;  and  from  drying  up  on  a  hot  dry  day. 

Sometimes  the  mouth  of  a  sebaceous  gland  gets  choked 
up,  and  then  its  secretion  collects  in  it  and  becomes  dark- 
colored.  In  this  way  little  black  specks  are  formed  on 
the  skin.  They  are  most  frequent  on  the  nose,  where 
the  sebaceous  glands  are  large,  though  the  hairs  to  which 
they  belong  are  very  small.  Pressure  between  the  finger- 
nails will  usually  easily  force  out  the  collected  secretion 
and  remove  the  speck. 

17.  Summary. — The  skin  forms  a  tough,  elastic,  protec- 
tive covering  for  the  body,  and  is  also  the  main  organ 
of  the  sense  of  touch. 

It  is  loosely  attached  to  parts  below  it,  so  that  it  can 
glide  over  them  in  our  movements,  without  being 
stretched  or  torn.  Beneath  it  is  a  cushion  of  fat  which 
protects  the  muscles  from  injury  by  blows. 

Another  use  of  the  fat  beneath  the  skin  is  to  check 
loss  of  heat  from  the  body.  Warm-blooded  animals 
which  live  in  the  sea,  as  whales,  have  a  very  thick  layer 
of  fat,  known  as  "  blubber,"  under  the  skin.  This 
enables  them  to  retain  their  animal  heat  in  spite  of  the 
cold  water  around  them.  For  the  same  reason,  a  fat  per- 
son can  bathe  longer  in  cold  water  without  being  chilled 
than  one  who  is  thin. 

17.  Functions  of  the  skin  ?  How  attached  to  parts  beneath  ?  Uses 
of  the  fat  under  the  skin?  Illustrate.  Layers  of  the  skin  ?  Characters 


SUMMARY.  69 

The  skin  consists  of  two  layers.  The  outer  or  epidermis 
is  not  sensitive  and  contains  no  blood.  The  outer  part  of 
the  epidermis  is  dry,  horny,  and  dead.  It  is  constantly 
being  shed. 

The  deeper  layer  of  the  epidermis  is  moist,  and,  being 
well  nourished  by  liquid  soaked  up  from  the  blood-ves- 
sels of  the  dermis,  grows  fast  and  makes  new  cells  which 
are  pushed  on  towards  the  surface  to  take  the  place  of 
those  of  the  outer  layer  which  are  shed  or  rubbed  off. 

The  dermis  contains  many  nerves  and  much  blood. 
An  important  use  of  the  epidermis  is  to  cover  and  pro- 
tect it.  If  there  were  no  epidermis,  our  whole  surface 
would  feel  like  the  "raw"  skin  at  the  bottom  of  a  blister. 

Nails  are  made  by  great  growth  of  the  horny  layer  of 
the  epidermis.  Their  function  is  protective. 

Hairs  are  scattered  over  nearly  the  whole  skin.  They 
are  threads  of  epidermis  developed  from  the  bottom  of 
little  pits  in  the  skin.  When  large  and  abundant,  as  on 
the  head,  they  protect  from  cold  and  blows.  Even  when 
small  and  few,  they  are  useful  by  aiding  in  the  sense  of 
touch. 

Glands  are  hollow  organs  which  make  special  liquids. 
The  liquid  made  by  a  gland  is  called  a  secretion,  and  is 
poured  out  through  a  tube,  the  duct  of  the  gland,  on 
some  surface  outside  or  inside  the  body.  The  sweat- 
glands  and  the  oil-glands  pour  their  secretion  on  the 
skin. 

The  sweat-glands  are  most  active  when  the  body  is 
warm,  and  help  to  keej^it  at  its  proper  temperature. 

of  outer  layer  of  epidermis  ?  Deeper  layer?  Characters  of  dermis? 
How  epidermis  protects  the  dermis?  Nails?  Hairs?  Uses? 
Glands?  Secretions?  Ducts?  Glands  of  the  skin?  Use  of  sweat- 
glands  ?  Of  oil-glands  ? 


70  SUMMARY. 

The  oil-glands  pour  their  secretion  into  the  hair-folli- 
cles. They  provide  a  sort  of  natural  hair-oil.  Their  se- 
cretion, also,  becomes  spread  over  the  skin  and  makes 
the  cuticle  slightly  greasy,  so  that  water  tends  to  run  off 
instead  of  soaking  into  it. 


CHAPTER  VII. 
HYGIENE   OF   THE    SKIN.— ANIMAL    HEAT.— CLOTHING. 

1.  Why  the  Skin  should  be  Kept  Clean. — A  film  tends 
to  collect  on  the  skin  daily.  This  film  consists  chiefly  of 
dry  dead  cells  from  the  surface  of  the  epidermis,  of  oily 
matter  from  the  sebaceous  secretion,  and  of  dust  and 
dirt.  A  certain  amount  of  sebaceous  secretion  is  useful 
for  reasons  already  given;  but  it  may  collect  in  harmful 
excess.  If  the  accumulation  of  the  above-named  matters 
is  not  regularly  removed  from  the  skin  it  tends  to  choke 
the  mouths  of  the  sweat-glands,  the  so-called  "pores  of 
the  skin,"  and  interfere  with  their  activity.  These  glands 
not  only  serve  to  regulate  the  heat  of  the  body,  but  sepa- 
rate waste  matters  from  it,  among  them  a  considerable 
amount  of  water  which  has  served  its  purpose  and  needs 
to  be  removed.  If  the  sweat-glands  do  not  work  well, 
other  organs,  the  lungs  and  kidneys,  whose  duty  it  also 
is  to  remove  water  and  wastes,  have  too  much  work 
thrown  upon  them.  The  entire  skin  should  therefore 
be  washed  every  day,  except  that  on  the  top  of  the  head. 
The  hair  takes  so  long  to  dry  that  it  is  not  usually  prac- 

i.  Of  what  is  the  film  composed  which  collects  on  the  skin  every 
day  ?  Why  should  it  be  removed  ?  What  are  the  pores  of  the  skin  ? 
The  uses  of  the  sweat-glands?  What  organs'  are  overworked  when 
the  sweat-glands  do  not  act  properly  ?  What  other  reasons  are  there 
for  keeping  the  skin  clean  ? 


?2  BA  THING. 

ticable  to  wash  the  head  oftener  than  once  or  twice  a 
week. 

No  doubt  many  folk  go  about  in  very  good  health 
with  very  little  washing;  contact  with  the  clothes  and 
other  external  objects  prevents  any  great  collection  of 
dirt  or  dead  epidermis  on  the  surface  of  the  skin.  But 
apart  from  the  duty  of  personal  cleanliness  imposed  on 
every  one  as  a  member  of  society  in  daily  intercourse 
with  others,  the  mere  fact  that  the  healthy  body  can 
manage  to  get  along  under  unfavorable  conditions  is  no 
reason  for  exposing  it  to  them.  The  evil  consequences 
may  be  experienced  any  day,  when  something  else 
throws  another  extra  strain  on  the  already  overworked 
lungs  and  kidneys. 

2.  Bathing. — A  bath  not  merely  cleanses  the  skin  but, 
when  of  the  proper  temperature  and  taken  at  the  right 
time,  strengthens  and  invigorates  the  whole  body.     For 
strong  healthy  persons,  a  cold  bath  is  the  best.    When  the 
water  is  very  cold  they  may  take  the  chill  off,  but  should 
not  make  it  warm.      For  the  delicate,  tepid  baths  may 
be  preferable, .but  should  be  very  brief.     Immediately 
after  a  bath  the  skin  should   be  dried  and  well  rubbed. 

3.  Effects  of  a  Cold   Bath.— The  first  effect  of  a  cold 
bath  is  to  drive  blood  from  the  skin  and  make   it  pale. 
This  is  soon  followed   by  a  reaction  in  which   the  skin 
becomes  red  and   full  of  blood,  and  a  pleasant  glow  of 
warmth  is  felt  in  it.     The  proper  time  to  come  out  of  a 
cold  bath   is  during  this   reaction.     If  the  stay  in  the 
water  be  too  long,  the  skin  again  becomes  pale  and  blood- 

2.  What  useful  purposes  are  served  by  bathing  ?     Proper  tempera- 
ture of  bath  ?     What  should  be  done  immediately  after  bathing  ? 

3.  Why  does  a  plunge   in  cold   water  make  the  skin   pale?     What 
follows  ?     When  should  one  come  out  of  a  cold  bath  ?    What  are  the 


COLD  BATtfS.  73 

less,  and  the  person  probably  feels  chilly,  depressed, 
and  uncomfortable  for  some  hours.  The  bath  has  then 
done  harm ;  it  has  weakened  instead  of  bracing  the  system. 

How  long  one  may  remain  in  cold  water  with  benefit, 
varies  with  the  temperature  of  the  water  and  with  the 
vigor  of  the  person.  A  strong  man  can  set  up  a  healthy 
reaction  after  a  much  longer  stay  in  the  water  than  can 
a  feeble  one.  Also  a  person  used  to  cold  bathing  may 
with  safety  continue  his  dip  longer  than  one  unaccus- 
tomed to  it.  Many  persons  who  have  been  taking  warm 
or  tepid  baths  all  the  rest  of  the  year,  injure  themselves 
in  the  summer  by  commencing  at  once  to  bathe  for 
twenty  minutes  or  more  in  the  sea.  Such  persons  com- 
plain that  sea-bathing  does  not  agree  with  them;  if  they 
would  begin  with  three  or  four  minutes  in  the  water,  the 
first  day,  and  gradually  increase  the  time,  they  would  in 
most  cases  be  benefited. 

4.  When  to  Bathe.— It  is  perfectly  safe  for  a  healthy  per- 
son to  take  a  cold  bath  when  warm,  provided  the  skin  is 
not  perspiring  profusely.  On  the  other  hand,  never  take 
a  cold  bath  when  you  are  feeling  chilly;  or  when  you  are 
much  fatigued  either  in  mind  or  body.  Under  such  cir- 
cumstances, the  proper  reaction  is  apt  not  to  occur.  A 
cold  bath  should  not  be  taken  soon  after  a  meal,  for  the 
blood  is  then  wanted  in  the  digestive  organs  (Chap.  XI.) 
and  cannot  be  spared  to  the  skin  to  set  up  the  after-glow. 
For  a  brief  daily  dip,  there  is  no  time  so  good  as  imme- 
diately after  rising,  while  the  body  is  still  warm  from 
bed  and  in  a  rested  vigorous  condition. 

consequences  of  staying  too  long  in  it?  State  the  conditions  which 
determine  the  length  of  time  it  is  wise  to  bathe  in  cold  water. 

4.  When  is  it  safe  to  take  a  cold  bath?  When  unwise?  What  are 
the  best  times  for  bathing  ? 


74  WARM  BATHS. 

5.  Shower-Baths  take  less   heat   from   the  body  than 
other  cold  baths.     The  falling  water  also  stimulates  the 
skin   and   aids    in    producing    the    after-glow.      Hence 
shower-baths  are  valuable  to  those  not   in   very   good 
health,  provided  they  suffer  no  unfavorable  reaction.      But 
the  sudden   shock  is   unfavorable  to  many  people;  es- 
pecially to  those  having  any  difficulty  with  the  heart. 
Persons  with  whom  shower  baths  agree,  frequently  find 
it  advantageous  to  stand  with  the  feet  in  tepid  or  warm 
water  while  taking  them,  and  to  keep  the  head  covered 
by  an  oilskin  cap.     They  thus  avoid  headaches  and  cold 
feet,  while  getting  the  general  benefit  of  the  bath. 

6.  Warm   Baths   cleanse   the   skin   more  readily   than 
cold,  and   are  desirable  once  or  twice  a  week  for  this 
purpose.     Daily  warm  baths  should  not  be  taken  except 
on  medical  advice.     While  promoting    the  tendency  to 
perspiration,  which  is  often  important  in  the  treatment 
of  disease,  they  also,  when  frequent,  diminish  the  general 
vigor  of  the  body. 

7.  The  Use  and  Abuse  of  Soap. — Nearly  all  soaps  con- 
tain so  much  potash  or  soda   that  lathers  made   from 
them  are  really  weak  "lye."     On  this  their  main  cleans- 
ing  power  depends;  for,  like   the  lye  used  to  remove 
stains    from    floors,    they   take    up  greasy   matters  and 
make  them   capable  of  being  washed   away  by  water. 
The  potash  or  soda  of  soap  often  does  harm,  causing  too 
free  removal  of  the  oily  sebaceous  secretion,  a  thin  layer 
of  which  is  necessary  to  protect  the  skin  from  too  rapid 

5.  In  what  circumstances  are  shower-baths  desirable  ?     What  pre- 
cautions should  delicate  persons  observe  in  taking  them  ? 

6.  What  are  the  uses  of  warm  baths?     Their  dangers  ? 

7.  What  makes  soap  cleansing  ?      How  may  it  injure  the  skin  ? 
How  should  its  use  be  limited  ?     Name  a  good  substitute  for  soap. 


COSMETICS.  75 

drying.  Probably  as  many  skin-diseases  have  been 
caused  by  too  free  use  of  soap,  as  by  uncleanliness.  Ex- 
cept on  parts  of  the  body  especially  exposed  to  contami- 
nation, soap  should  not  be  applied  oftener  than  twice  a 
week.  More  frequent  employment  of  it  is  quite  un- 
necessary for  cleanliness,  if  a  daily  bath,  followed  by  a 
good  rubbing  with  the  towel,  be  taken.  Persons  whose 
skin  is  injured  by  even  the  occasional  use  of  soap,  will 
find  in  corn-meal  a  good  substitute. 

8.  Cosmetics  and  Hair-Dyes.— When  the  face  is  hot 
and  perspiring,  a  good  deal  of  comfort  may  often  be  ob- 
tained by  applying  a  little  finely  powdered  arrowroot, 
and  immediately  wiping  it  off  with  a  dry  towel.  This 
is  better  than  plunging  the  face  in  water,  which  often 
causes  it  to  become  more  flushed  afterwards.  No  face- 
wash,  whitening,  rouge,  or  other  coloring  matter  should 
ever  be  used.  In  spite  of  the  assertions  of  their  makers, 
which  induce  foolish  folks  to  buy  them,  nearly  every 
one  contains  materials  highly  injurious  to  the  skin. 
Those  which  do  not,  are  hurtful  by  interfering  with  the 
proper  growth  of  the  epidermis  and  by  checking  the 
action  of  the  sweat-glands.  Many  face-washes  contain 
poisons  which,  being  absorbed  by  the  skin,  ruin  the 
health. 

Most  hair-dyes  contain  lead  or  some  other  poison.  As 
they  are  kept  off  the  skin  as  much  as  possible,  they  do 
not  in  most  cases  injure  it,  but  they  always  harm  the 
hair,  never  improve  its  appearance,  and  seldom  succeed 
in  their  purpose  of  deceit. 

8.  State  a  harmless  method  of  quickly  cooling  a  heated  face.  Why 
should  face-washes  and  other  "cosmetics"  be  avoided?  Why  hair- 
dyes  ? 


?  ACTION  OF  ALCOHOL   OAT   THE   SKIN. 

9.  Burns  and  Scalds.— If  slight,  cloths  soaked  in  strong 
solution    of  bicarbonate  of  soda  (common  washing  or 
cooking  soda)  may  be  applied,  and   renewed  when   they 
begin  to  dry.     This  greatly  relieves   the   pain.     If  the 
burn  or  scald  be  deep  and  extensive,  endeavor  to  exclude 
the  air  and  prevent  rubbing  until  medical  aid  can  be  ob- 
tained.    The  best  application  for  these  purposes,  is  raw 
cotton  soaked  in  a  mixture  of  linseed-oil  and  lime-water 
in  equal  parts.     If  this  is  not  at  hand   (as  it  should  be 
in  every  house  distant  from  a  drugstore),  sweet-oil   or 
fresh  lard  may  be  used  instead. 

10.  Action  of  Alcoholic  Drinks  on  the  Skin. — Taken  into 
the   body  in  any  form,    alcohol  causes  more   blood    to 
flow  to  the  skin.     This  is  seen  in  the  flushed  face   of  a 
man  who  has  been  "  drinking."     If  the  drinking  be  con- 
tinued, the   redness    becomes   permanent.     The   skin   is 
then  puffy  and   congested,    and   the    face  especially  ac- 
quires a  reddish  blotchy  look.     Its  proper  nourishment 
being   interfered  with,  the    epidermis   collects   in    scaly 
masses.     The  peculiar  degraded  look  of  the  sot's  face  is 
the  result. 

11.  Animal  Heat. — Sometimes  you  feel  hot,  sometimes 
cold.     This  feeling  is  due  to  changes  in  your  skin.     The 
mouth  may  feel  hot  after  drinking  a  cup  of  tea,  or  cold 
for  a  short  time  after  eating  ice-cream:  but  this  does 
not  make  us  say  that  we,  that  is  our  bodies  in  general, 
feel  warm  or  cold. 


9.  What  handy  remedy  is  useful  for  slight  burns  ?     What  should  be 
done  in  case  of  severe  burns  or  scalds  ? 

10.  How  does  "  drinking"    affect  the  skin  ?     The  expression  ? 

11.  To  what  are   "feeling  hot"  and  "feeling  cold"  due?     Illus- 
trate.    What  is  "animal  heat"? 


TEMPERATURE   OF   THE  BODY.  77 

If  you  keep  your  mouth  closed,  your  tongue  does  not 
feel  warm  on  a  hot  day,  or  cold  when  the  air  around  you 
is  at  a  freezing  temperature.  The  reason  of  this  is  that 
in  your  body  heat  is  being  produced  all  the  time,  keep- 
ing the  internal  parts  warm.  This  heat  is  known  as  ani- 
mal heat. 

12.  The  Temperature  of  the  Body. — So  long  as  you  are 
in  health,  a  thermometer  placed  in   your  mouth  would 
indicate  almost  exactly  the  same  temperature  every  day 
in  the  year.     This  is  a  very  curious  fact.     A  stone  or  a 
frog  is  cold  on  a  cold  day  and  warm  on  a  hot  day;  but, 
except  sometimes  on   the  outside,  your  body  is  always 
hot,  and  hot  to  very  nearly  the  same  degree;  in  health 
never  below  98°  or  above  101°  of  an  ordinary  Fahrenheit 
thermometer.     All  animals,  as  birds  and  beasts,  which, 
like  man,  have  a  regular  temperature  of  their  own,  are 
known  as  "warm-blooded"  animals.     Any  condition  of 
the  body  in  which  its  organs  are  hotter  than  their  proper 
temperature,  is  known  as  a  "fever." 

13.  How  the  Body  is  kept  from  getting  too  Hot. — Every- 
thing that  works,  even  two  sticks    rubbed  across  each 
other,  produces  heat,  though  in  many  cases  it  is  too  slight 
to  be  noticed.     The  organs  of  our  bodies  are  no  excep- 
tion; and  the  more  they  work,  the  more  heat  they  pro- 
duce.    If  all  this  heat  remained  in  the  body,  we  should 
soon  be  in  a  high  fever.    It  is  carried  off  in  several  ways. 

12.  What  does  a  thermometer  placed  in  the  mouth  show  ?     How 
does  your  body  differ  as  to  temperature  from  a  stone  or  a  frog  ? 
What  is  the  healthy  temperature  of  the  interior  of  the  human  body  ? 
What  is  meant  by   "  warm-blooded  animals"  ?     What  is  fever? 

13.  Where  is  heat  produced  in  the  body?    When  most?  Why  must 
some  of  it  be  got  rid  of?     How  do  the  lungs  help  in  keeping  us  from 
becoming  too  warm  ?    The  sweat-glands  ?   The  blood  flowing  through 
the  skin  ? 


78          REGULATION  OF  BODILY  TEMPERATURE. 

Partly,  for  example,  by  the  air  we  breathe  oat,  which  is 
nearly  always  hotter  than  the  air  we  breathe  in:  and  so 
carries  heat  away  from  the  body.  But  the  skin  does 
more  than  any  other  organ  in  regulating  the  bodily 
temperature. 

The  skin  gets  rid  of  the  heat  in  two  ways.  In  the  first 
place,  its  glands  produce  perspiration,  and  the  evapora- 
tion of  this  perspiration,  as  we  have  already  learned, 
carries  off  heat  (p.  67).  We  thus  see  why  it  is  useful  that 
we  perspire  more  freely  on  a  hot  day,  or  when  we  are  ex- 
ercising and  our  muscles  producing  a  great  deal  of  heat. 

In  the  second  place,  except  on  the  very  hottest  sum- 
mer days,  the  air  around  us  is  cooler  than  the  inside  of 
our  bodies.  Blood  which  has  been  made  hot  as  it 
flowed  through  the  internal  organs,  is  sent  to  the  skin 
and  there,  giving  heat  to  the  air,  is  cooled.  It  is  then 
carried  back  from  the  skin  to  the  inside,  picks  up  more 
heat,  flows  again  to  the  surface  and  gets  rid  of  it;  and 
so  on,  all  the  time. 

14.  How  the  Body  is  kept  from  getting  too  Cold. — The 
fat  which  lies  beneath  the  skin  may  be  compared  to  the 
packing  in  the  sides  of  a  refrigerator.  It  checks  the  pas- 
sage of  external  heat  or  cold  to  the  inside.  Accordingly, 
thin  persons  cannot  bear  exposure  to  cold  as  well  as 
those  who  are  fat.  Too  great  loss  of  heat  is  also  pre- 
vented by  the  diminished  activity  of  the  sweat-glands  in 
cold  weather,  and  by  the  fact  that  most  of  the  blood  is 
then  kept  away  from  the  skin,  which  accordingly  becomes 
pale.  An  exception  to  this  is  found  when  there  has  been 

14.  How  does  fat  aid  in  keeping  us  from  too  great  cooling  ?  How 
do  the  sweat-glands  behave  in  cold  weather?  Why  does  the  skin 
usually  become  pale  in  a  cold  room  ?  When  may  the  skin  be  red 
and  perspiring  even  in  cold  weather  ? 


CLOTHING.  79 

great  production  of  heat  in  the  internal  organs.  Then 
the  sweat-glands  act,  and  the  skin  becomes  full  of  blood 
even  on  a  winter's  day.  You  know  that  if  you  sit  still 
in  a  cold  room  your  skin  becomes  pale  and  you  do  not 
perspire;  while,  so  long  as  you  are  in  health,  a  good  run 
in  the  coldest  weather  will  flush  the  skin  and  cause  per- 
spiration. 

15.  Clothing. — Clothes   are  employed  by  mankind  for 
many  purposes  of  ornament  and  ostentation;  and  these 
unimportant   uses   are   sometimes  allowed    to    interfere 
very  seriously  with  their  main  objects.     The  real  uses  of 
clothing  are  physiological  and  hygienic.  These  uses  are, 
(i)  to  aid  the  skin  in  regulating  the  temperature  of  the 
body;  (2)  to  protect  the  skin  itself  from  too  rapid  heat- 
ing or  cooling;  (3)  to   prevent  a  sudden   rush  of  blood 
from  the  skin  to  internal  organs  when  the  air  around  the 
body  is  quickly  cooled. 

16.  What  Properties  the   Materials  used  for   Clothing 
should  Possess. — Nature  has  provided  all  warm-blooded 
animals  who   thrive    in    parts   of   the   earth  where    the 
climate  is  variable,  except  man,  with  a  covering  of  fur  or 
feathers.      This   covering  becomes  thicker  in  the  cold 
seasons  of  the  year,  and  thinner  in  the  warm.     It  also  is 
made  of  materials  which  greatly  hinder  the  passage  of 
heat   through  them.     Fur  and  feathers  are  accordingly 
known  as  bad  conductors  of  heat.     In  winter  they  check 


15.  For  what  unimportant  uses  is  clothing  employed  ?     What  its 
real  uses  ? 

16.  What   clothing  does  Nature   provide  for   most  warm-blooded 
animals?     How  does  it  change  with  the  seasons?   What  are  the  prop- 
erties of  its  materials  as  regards  the  transmission  of  heat  ?     How  do 
fur  and  feathers  protect  the  skin  from  sudden  changes  of  tempera- 
ture ?     What   lessons  should  man  learn  from  the  clothing  provided 
for  lower  animals  bv  Nature? 


o  CLOTHING  MATERIALS. 

loss  of  heat  from  the  skin;  and  all  the  year  round  they 
keep  the  skin  from  being  rapidly  cooled  or  heated  when 
exposed  to  sudden  changes  in  temperature. 

Man  has  to  provide  his  own  clothing,  but  should  al- 
ways bear  in  mind  this  lesson  from  Nature:  His  cloth- 
ing should  vary  in  amount  with  the  season,  but  the  chief 
garments  should  be  made  of  materials  which  are  bad 
heat-conductors. 

17.  The  Relative  Value  of  various  Clothing  Materials. — 
Furs  are  very  bad  conductors,  and  do  not  easily  be- 
come damp.  They  are  the  most  suitable  clothing  for 
very  cold  weather.  Woollen  fabrics  are  also  excellent. 
Silk  comes  after  wool,  and  in  our  variable  climate  forms 
the  best  material  for  the  underclothing  of  those  whose 
skins  are  irritated  by  woollen  materials,  such  as  merino. 
Cotton  is  not  so  good  as  silk,  but  is  far  better  than  linen, 
which  not  only  allows  heat  or  cold  to  pass  readily 
through  it,  but  easily  absorbs  moisture  and  becomes 
damp.  The  same  objection  holds  against  linen  bed- 
clothing.  Cotton  should  be  used,  except,  perhaps,  for 
pillow-cases  in  summer. 

The  proper  clothing  will  vary  with  climate  and  sea- 
son; but,  except  for  those  living  in  regions  where  sudden 
temperature-changes  do  not  occur,  the  following  is  the 
proper  rule:  Wear  silk  or  wool  next  the  skin;  over 
this  regulate  the  amount  of  clothing  according  to  the 
weather,  but  always  wear  at  least  one  other  covering  of 
non-conducting  material,  cloth,  silk,  or  flannel. 


17.  Name  common  materials  for  clothing  in  order,  putting  the 
worst  conductors  of  heat  first.  Why  is  linen  not  so  good  a  clothing 
material  as  cotton  ?  What  rule  as  to  clothing  should  be  observed  by 
all  who  live  in  a  variable  climate  ? 


CHAPTER  VIII. 
FOODS. 

1.  How  the  Body  is  Built  up  and  Repaired. — So  long  as 
you  are  growing,  you  require  a  supply  of  material  out  of 
which  your  body  can  make  more  bone  and  muscle  and 
skin  and  blood,  and  the  rest.     This  material  is  supplied 
in  the  things  you  eat  and  drink. 

Even  after  a  man  is  full-grown,  he  still  needs  a  quan- 
tity of  food  daily,  to  repair  his  body.  Every  time  an  or- 
gan works,  some  of  it  is  used  up  and  turned  into  useless 
waste  things,  which  are  soon  carried  away  from  the  body 
through  the  pores  and  other  outlets.  If  they  are  kept 
in  it,  as  they  sometimes  are  in  disease,  they  clog  all  the 
organs  and  interfere  with  their  work.  If  a  man  be  starved, 
he  becomes  lighter  every  day,  because  he  makes  waste 
matters,  and  these  are  carried  away  by  the  skin  or  the 
lungs  (Chap.  XV.)  or  the  kidneys  (Chap.  XVII.)  or  other 
organs,  all  the  time  so  long  as  he  lives. 

2.  The  First  Use  of  Foods  is,  then,  to  furnish  materials 
for  the  building  and  repair  of  the  body.     In  early  life, 
the  building  exceeds  the  waste,  and  growth  takes  place. 


1.  What   does  the  body   require  while  growing?     How  supplied? 
Why  does  a  full-grown  man  need  food  ?     Why  must  the  wastes  of  the 
body  be  removed  ?    Why  does  a  man  become  lighter  if  he  takes  no 
food? 

2.  What  is  the  first  use  of  foods  ?     Why  do  we  grow  while  young  ? 
Why  not  in  middle  age  ?     What  often  happens  in  old  age  ? 


82  OX  ID  A  TION. 

Then  comes  a  period  of  middle  life,  in  which  they  are 
about  equal.  Finally,  in  old  age,  it  often  happens  that 
the  organs  cannot  make  use  of  enough  food  for  their 
complete  repair,  and  therefore  slowly  diminish  in  size. 
The  muscles  and  bone  of  an  old  man  often  become 
"  wasted"  and  feeble. 

3.  A  Second  Use  of  Foods  is  to  give  us  strength  and 
keep  up  our  animal  heat,     A  starving  man  not  only  be- 
comes lighter  every  day,  but  weaker  and  colder.     This 
use  of  foods  may  be  compared  to  the  use  of  coal  in  the 
furnace  of  a  steam-engine.     And  just  as  the  coal  would 
be  useless  if  it  did   not  burn,  and  will  not  burn  unless 
there  be  a  draught  of  air  in  the  furnace,  so  foods  would 
neither  make  us  strong  nor  warm   did  they  not  contain 
things  which  could  very  gently  burn   inside  the  body; 
and  in  order  to  burn,  these  things  must  be  supplied  with 
air  by  our  breathing. 

4.  Oxidation. — The   air  which   we    breathe    into    our 
bodies  is  a  mixture  of  two  gases;  only  one   of  them  is 
useful  in  keeping  a  fire   alight    or   in    burning    foods 
inside   our    bodies.      It    is    named    oxygen.      Generally 
when    anything   burns,    it    unites    with    oxygen.      The 
thing  burned  is  then  said  to  be  oxidized,  and  the  process 
of  uniting  with  oxygen  is  named  oxidation.     When  oxi- 
dation takes  place  very  fast,  a  great  deal  of  heat  is  given 
out  along  with  light,  as  in  a  fire   or  candle.     But  oxida- 
tion sometimes  goes  on  slowly;  and   then  the  tempera- 

3.  What  is  the  second  use  of  foods  ?     How  shown  ?     To  what  may 
the  use  of  foods  be  compared  ?     In  order  that  a  fire  may  burn  what  is 
necessary  besides  coal  or  wood  ?     What  must  food  contain  ?    What 
is  necessary  that  these  things  may  burn  ?     How  is  it  supplied  ? 

4.  What  is  oxygen  ?    When  is  anything  said  to  be  oxidized  ?    What 
is  oxidation  ?     What   are  the  effects    of  rapid  oxidation  ?     Of  slow  ? 
Which  kind  of  oxidations  occurs  in  our  bodies  ?     Why  ? 


DEFINITION  OF  FOODS.  83 

ture  does  not  become  very  high  and  no  light  is  produced. 
The  oxidations  which  take  place  in  our  bodies,  are  of 
course  slow  oxidations;  otherwise  they  would  burn  us 
to  ashes. 

5.  Examples  of  Slow  Oxidation. — A  good  example  of  a 
slow  oxidation  is  afforded  by  the  rusting  of  iron;  this  is 
an  oxidation;  and  the  rust  is  iron   united  with  oxygen. 
This  oxidation  usually  occurs  even    more   slowly  than 
those  which  take  place  in  our  bodies,  and  heat  is  given 
off   so   slowly   that   rusting   iron   does   not    feel   warm 
when  we  touch  it.     You  know,  too,  that  iron  rusts  easily 
in  damp  air,  and  in  this  respect  the  oxidation  of  the  iron 
is  like  the   oxidations    which  occur  inside    our  bodies, 
which  are  moist  in  every  part. 

6.  Definition  of  Foods. — Foods  include  all  substances,  ex- 
cept air,  taken  into  the  body  and  serving  for  any  one  of  three 
purposes — (i)  to  provide  material  for  its  growth  or  repair,  or 
(2),  by  their  oxidation,  to  supply  it  with  working  power  or  to 
keep  it  warm,  or  (3)  to  aid  in  carrying  nourishment  from 
part  to  part.     To  the  above,  we  must  add  that  for  a  sub- 
stance to   be   properly  a  food,  neither  itself  nor  anything 
produced  from    it  inside  the  body   shall  be  injurious   to  the 
structure  or  action  of  any  organ;  otherwise  it  would  be  a 
poison,  not  a  food. 

Most  foods  serve  more  than  one  purpose.  Thus  meat 
and  bread  furnish  material  for  growth  and  repair,  and 
also  supply  strength  and  warmth.  Water  is  found  in  all 
the  organs,  and  is  a  necessary  part  of  them;  but  it  also 

5.  Give  an  example  of  slow  oxidation.     In  what  other  respect  does 
the  rusting  of  iron  resemble  the  oxidations  which  take   place  in  our 
bodies  ? 

6.  Define  foods.     Poisons.     What  purposes  are  served  by  meat 
and  bread  ?     By  water  ?     Illustrate. 


84  NOURISHING   SUBSTANCES  OF  FOODS. 

dissolves  solid  foods  and  carries  them  into  the  blood 
to  be  conveyed  to  places  where  they  are  needed.  A 
lump  of  sugar  in  your  mouth  would  not  nourish  you, 
unless  the  saliva  should  dissolve  it,  and  then  it  should 
be  taken  up  into  the  blood  and  borne  to  muscle  or  brain 
or  skin,  or  some  other  part  that  wanted  new  material. 

7.  Classification  of  Foods.— Foods,  like  the  body  itself, 
consist  of  both  things  which  will  not  burn  or  oxidize,  and 
things  which  will.     The  food-materials  which   will  not 
burn,  such  as  water  and  common  salt,  are  known  as  in- 
organic foods.     The  foods  which  will  burn,  are   obtained 
either  from  animals  or  plants,  and  are  named  organic 
foods,   because   they   are    obtained    from    living   things, 
which  have  organs. 

8.  Most  Foods  contain  more  than  one  Nourishing  Sub- 
stance.— Beef,    for  example,   contains  (i)   water,    which 
goes  off  when  we  dry  it;   (2)  certain  minerals,  which  are 
left  in  the  ashes  if  the  meat  be  burned,  and  which,  when 
meat  is  eaten,  are  useful  in  building  bone,  blood,  muscle, 
and  brain;  (3)  organic  matters  of  several  kinds:    the  fat 
is  one  of  them;  another,  found  in  the  lean,  is  named  an 
albumen.     It  is  in  nearly  all  respects  like  the  white  of  an 
egg.     To  take  another  example,  wheaten  bread  contains 
(i)  some  water;  (2)   minerals;    (3)    a  kind    of  albumen; 
(4)  starch;  (5)   a  little  fatty  matter.     Each    nourishing 
substance  found  in  any  food,  is  named  a  food-stuff '. 

9.  The  Chief  Kinds  of  Organic  Food-Stuffs  are— (i)  albu- 


7.  Of  what  do  foods  consist?  What  are  inorganic  foods  ?  Examples. 
Organic?     From  what  obtained?     Why  so  named  ? 

8.  What  substances,  useful  to  the  body,  does  meat  contain  ?    What 
does   the   albumen    resemble?     What   are   the   useful   substances  in 
bread  ?     What  is  a  food  stuff  ? 

9.  Name  the  chief  organic  food  stuffs. 


INORGANIC  FOOD-STUFFS.  85 

mens;  (2)  jelly-forming  substances;  (3)  fatty  or  oily 
matters;  (4)  sugars;  (5)  starch.  The  albumens  are  the 
most  important.  A  man  can  maintain  life  on  water  and 
lean  meat,  while  if  he  should  get,  along  with  plenty  of 
water,  all  the  fat  and  sugar  and  arrowroot  (which  is 
nearly  pure  starch)  that  he  could  eat,  he  would  slowly 
starve. 

The  reason  of  this  is  very  simple.  A  special  substance, 
named  nitrogen,  is  essential  for  the  making  or  repairing 
of  all  the  organs  of  the  body.  Albumens  contain  some 
of  this  substance;  fat,  starch,  and  sugar  do  not.  Every 
day  some  nitrogen  is  carried  away  from  the  body  in  its 
waste  matters.  If  none  of  it  be  supplied  -in  the  food,  a 
man  will  therefore  slowly  die  of  nitrogen-starvation,  no 
matter  what  abundance  he  may  have  of  other  things. 

Crackers  and  cheese  would  be  useless  to  a  man  dying 
of  thirst;  so  fat  or  sugar  or  starch  would  be  useless  to  a 
man  whose  organs  were  starving  for  nitrogen. 

10.  Inorganic  Food-Stuffs. — A  sufficient  quantity  of 
most  of  these  is  contained  in  bread  and  meat  and  milk 
and  our  other  common  foods.  Thus  iron  is  an  essential 
part  of  the  blood,  but  in  health  we  need  no  more  than 
is  contained  in  the  vegetables  and  meat  which  we  eat 
daily. 

Water  and  common  salt  are  the  only  inorganic  food- 
stuffs that  are  usually  taken  by  themselves  or  specially 
added  to  our  food  in  cooking.  The  body  daily  gives 
off  more  of  each  than  it  would  otherwise  receive. 

Which  are  the  most  important?  How  do  we  know  that  the  others 
are  less  valuable  ?  Explain  why  starch  and  fat  cannot  take  the  place 
of  albumens  in  nourishing  the  body.  Illustrate. 

10.  How  are  we  supplied  with  most  inorganic  food-stuffs  in  suffi- 
cient quantity  ?  Illustrate.  How  are  water  and  common  salt  excep- 
tional ?  Why  ? 


86  SAL  T.  —ME A  TS.  —MILK. 

11.  Common  Salt  is  found  in  every  solid  part  and  every 
liquid  of  the  body.     It  has  been  maintained  that  salt  as 
a  separate  article   of  diet  is   a  mere  luxury,  and   there 
seems  to  be  some  evidence  that  certain  savage  tribes  live 
without  more  than  they  get  in  the   meat   and  vegetables 
which   they  eat.     There   is,  however,  no  doubt  that  to 
many  animals,   as  well   as   most   men,    the  want  of  salt 
is  a   terrible    deprivation.      Buffaloes   and    other    crea- 
tures  are    well  known    to    travel    miles  to  reach  "salt- 
licks;" of   two    sets    of   oxen,    one   allowed    free   access 
to  salt,  and  the  other  given  none  save  what  existed   in 
their  ordinary  food,  it  was  found  after  a  few  weeks  that 
the  former  were  in  much  better  condition.     In  man  the 
desire  for  salt   is    so   great   that  in  regions  where   it  is 
scarce,  it  is  used  as  money.     In  some  parts  of  Africa,  a 
small  quantity  of  salt  will  buy  a  slave,  and  to  say  that  a 
man  commonly  uses  salt  at  his  meals,  is  equivalent  to 
stating  that  he  is  a  luxurious  millionaire. 

12.  Meats,  whether   derived    from  bird,  beast,  or  fish, 
are   highly   valuable   foods.     They   supply   material  for 
making  tissues,  for    providing  working  power,  and  for 
keeping  up  animal  heat. 

13.  Milk  will  support  life  longer  than  any  other  single 
food.     It   contains   water,  minerals,  a   kind   of  albumen 
named  casein,  which,  when  separated,  forms  cheese;  fatty 
matters,  especially  butter;  and  a  sugar  named  milk-stigar. 
In    milk    there   is    more   lime  than   any   other  common 
food;  it.  is   therefore  very  valuable   in   childhood  when 
the  bones  are  growing  rapidly. 

11.  In  what  parts  of  the  body  is  common  salt  foun  J  ?    What  is  said 
to  result  from  want  of  it  ?     Illustrate  the  natural  longing  for  salt? 

12.  What  is  said  of  the  value  of  meats  ? 

13.  Why  is  milk  a  very  valuable  food?     Name  the  chief  food-stuffs 
contained  in  it.     Why  is  it  especially  valuable  in  childhood  ? 


EGGS.— BREAD.—  VEGE  TABLES  AND  FR  UITS.       8/ 

14.  Eggs  are  rich  in  albumen  and  fats.     They  contain 
a  great  deal  of  valuable  nourishment  in   a  small  bulk. 
The   white,  or  albumen,    is   more  easily  digested    when 
cooked    soft,  and  the  yolk  when  cooked    hard.     So    in 
the    old  controversy  about  hard-boiled   and   soft-boiled 
eggs,  as  in  a  good  many  controversies,  both  sides  are 
wrong  and  both  sides  are  right. 

15.  Bread  made  from  wheaten  flour  is  more  nourishing 
than  any  other,  as  it  contains,  besides  much  starch  and 
a  little  sugar  and  fat,  a  good  deal  of  a  kind  of  albumen 
named  gluten.     In  preparing  ordinary   white   flour,   the 
husk  of  each  grain  of  wheat  is  sifted  out  by  a  process 
known  as  bolting.     This  husk  contains  a  good   deal  of 
nourishing    matter.       In    unbolted    flour    this    is   saved. 
Many  persons  also  find  bread  made  from  it  more  whole- 
some than  that  made  of  bolted  flour.     In  other  cases  it 
unduly  irritates  the  bowels.    Maize  or  corn  contains  more 
starch  and  fats  than  wheat,  but  much  less  albumen. 

16.  Vegetables  and  Fruits. — Rice  contains  a  great  deal 
of  starch  but  hardly  any  albumen:  by  itself  it  is  a  very 
poor  food,  but  taken  with  food  rich  in  albumen,  as  meat 
of  any  kind,  it   is  excellent.     Peas  and   beam  are  good 
foods:  they  contain  much  albumen  and  starch.     Potatoes 
are  a  poor  food.     Other  fresh  vegetables,  as  cabbage,  tur- 
nips, and  tomatoes,  are  useful  mainly  for  the  mineral  mat- 
ters   contained   in   them.     Most   of  their  weight  is   due 

14.  What  do  eggs  contain  ?     When  are  they  more  easily  digested  ? 

15.  What  is   the    most  nourishing    kind   of  bread?     Why?     What 
is  meant  by  the  "bolting"  of  flour  ?     What  is  saved  when  flour  is  un- 
bolted ?     What  is  said  of  the  healthfulness  of  eating  bread  made  from 
unbolted  flour?     How  does  corn  differ  in  composition  from  wheat? 

16.  What  is  said  of  rice?     Of  peas  and  beans?     Potatoes?     Other 
fresh  vegetables?     What  is  their  chief  constituent ?     What   is   said  of 
fruits  ?     Give  proof  of  their  value. 


88  JELL  Y. 

simply  to  water;  organic  food-stuffs  are  present  in  them 
in  very  small  quantity.  Fruits,  like  most  fresh  vegeta- 
bles, are  chiefly  valuable  for  their  mineral  matters.  Some 
kind  of  fruit  or  vegetable  is,  nevertheless,  an  important 
part  of  every  one's  diet.  This  is  shown  by  the  fact  that 
sailors  on  a  long  voyage  almost  invariably  suffered  from 
the  disease  known  as  scurvy,  before  the  "  canning"  of 
vegetables  and  fruits  made  it  possible  to  keep  the  crew 
supplied  with  them. 

17.  Jelly. — Jellies   made   from   animal  substances,   as 
calves'  feet,  or  the  gelatin    sold    in    groceries,  are    com- 
monly believed   to  be  extremely  nutritious.     It  is  there- 
fore   important    to    know   that,  although    they    contain 
nitrogen,  they   cannot   entirely  take   the  place   of  albu- 
mens.    When  our  bodies  are  supplied  with  animal  jelly, 
they  can  manage  to  get  along  with  less  albuminous  food, 
but  the  organs  need  for  their  growth  or  complete  repair, 
food    containing  some    albumen.     If  a  sick  person  can 
digest  some  lean  beefsteak,  it  is  more  valuable  as  a  food 
than  the  best  calf's-foot  jelly;  but  if  he  can  only  digest 
the  jelly  it  is  very  useful,  because,  though  it  does  not 
entirely  prevent  the  loss  of  nitrogen   from  the  body,  it 
considerably  lessens  it. 

18.  The  Cooking  of  Meats,  in  many  cases  causes  special 
flavoring  matters   to   be   formed,  which   make  our  food 
more  palatable.     In  addition  it  makes  many  foods  more 
digestible. 

When  meats  are  properly  cooked  they  become  softer 

17.  What  jellies    are   usually   supposed    to    be   very   nourishing  ? 
What  is  it  important  to  know  about  them  ?     How  and  when  may  they 

be  very  useful  ? 

18.  How  does  cooking  make  meats  more  pleasant  to  the  taste  ? 


COOKING.  89 

and  more  easily  broken  up  by  the  teeth  because  their 
connective  tissue  loses  its  toughness,  being  for  the  most 
part  turned  into  jelly.  If  the  meat  be  cooked  too  fast 
this  change  occurs  very  imperfectly,  and  it  comes  to 
table  stringy,  tough,  unpleasant  to  eat,  and  hard  to  di- 
gest. 

When  meat  is  boiled,  much  of  its  flavoring  and  some  of 
its  nourishing  matters  are  apt  to  pass  out  into  the  water 
and  be  lost.  If  the  meat  be  plunged  at  first  into  boiling 
water  for  a  few  minutes,  the  surface  is  hardened  and  a 
coating  formed,  which  keeps  in  the  flavoring  matters  of 
the  deeper  parts.  The  cooking  should  then  be  continued 
slowly.  Quick  boiling,  except  at  the  start,  will  spoil  the 
best  and  most  tender  piece  of  meat. 

Hogs  are  especially  apt  to  suffer  from  a  parasite,  which 
lives  in  their  muscles.  This  parasite  is  a  little  worm 
named  trichina.  If  the  meat  be  eaten  raw  or  imperfectly 
cooked,  these  parasites  bore  their  way  out  of  the  alimen- 
tary canal  and  travel  all  over  the  body,  producing  the 
disease  known  as  trichinosis.  This  danger  may  be  avoid- 
ed by  thorough  cooking,  which  kills  the  trichinae. 

19.  The  Cooking  of  Many  Vegetables  is  very  important. 
Those  which  are  not  eaten  in  the  green  state  for  their 
minerals,  nearly  all  contain  starch  as  their  chief  constitu- 
ent. This  starch  exists  in  the  form  of  tiny  solid  parti- 
cles which  are  very  hard  to  digest.  When  the  vegetable 
is  boiled,  these  particles  are  softened  and  made  easier  to 

More  digestible  ?  Why  should  they  be  cooked  slowly?  Why  should 
a  joint  which  is  to  be  boiled  be  put  at  first  in  very  hot  water?  Why 
should  the  cooking  be  finished  slowly?  Why  should  hog-meat, 
especially,  be  thoroughly  cooked  ? 

19.  What  is  the  chief  nutritive  substance  in  vegetables  ?  How  is  it 
altered  by  boiling  ?  By  roasting? 


90  COOKING, 

digest.  When  starch  is  roasted,  it  is  converted  into  a 
substance  known  as  soluble  starch  which  readily  dissolves 
in  the  mouth  or  stomach.  The  common  belief  that  the 
crust  of  a  loaf  is  more  easily  digested  than  the  crumb, 
and  toast  than  ordinary  bread,  is  therefore  correct. 


CHAPTER   IX. 

STIMULANTS. 

1.  What  is  Meant  by  a  Stimulant. — In  general  a  stimu- 
lant is  something  that  does  not   nourish   the   body,  but 
stirs  it  or  one  or  more  of  its  organs  to  do  work.     Thus 
we  say  that  a  man  is  stimulated  to  labor  by  the  desire 
to  make  his  family  comfortable;  or  a  lad  to  hard  study 
by  the  wish  to  get  to  the  head  of  his  class;  or  to  the  use 
of  his  muscles  to  their  utmost  power,  by  the  ambition  to 
win  a  race.     Some  stimulus  to  exertion   is  useful:  with- 
out it  most  of  us  would   be  slothful  and  ignorant  and 
stupid.     On  the  other  hand,  our  bodies  may  be  stimu- 
lated to  attempt  more  than  they  can  safely  accomplish. 
Many  a  man  breaks  down  from   too  severe  labor,  and 
boys  and  girls  at  school  sometimes  injure  their  health 
by  overstudy,  stimulated  by  the  ambition  to  excel. 

2.  Foods  as  Stimulants. — Several  common  articles  of 
diet  are  named  stimulants,  because  their  action  is  rather 
to  excite  the  brain,  or  the  heart,  or  the  muscles,  or  the 
stomach  to  greater  activity,  for  a  time,  or  to  decrease  the 
feeling  of  fatigue  after  labor,  than  to  nourish  any  organ. 
Some  of  these  stimulants,  as  pepper,  which  makes  many 

1.  What  is  meant  by  a  stimulant?     Illustrate.     Why  is  some  stim- 
ulus useful?     How  may  it  be  an  evil  ? 

2.  Why  are    several    common   articles  of   diet  called  stimulants? 
What  is  said  of  their  different  effects?     Of  those  who  need  not  even 
the  least  injurious  ? 


92  USE   OF  STIMULANTS. 

foods  more  palatable,  do  little  or  no  harm  as  ordinarily 
used.  Others,  as  alcohol  in  all  its  forms,  when  taken  at 
all  are  very  apt  not  to  be  used  in  moderation,  and  then 
they  do  so  much  injury  that  they  are  really  poisons. 
Persons  in  perfect  health  need  no  kind  of  stimulant  food. 
A  strong,  healthy  young  person  with  rich  blood,  power- 
ful heart,  vigorous  muscles,  and  good  digestion  wants 
no  pepper  nor  mustard  nor  tea  nor  coffee  to  promote  his 
appetite  or  relieve  his  fatigue.  He  is  better  without 
such  things;  and  so  is  a  perfectly  healthy  man  or  wo- 
man. 

3.  The  Use  of  Stimulants. — Stimulant  articles  of  diet 
are  rather  medicines  than  foods;  as  medicines  they  have 
their  use.     A  man  sometimes  comes  home  after  his  day's 
work,  fagged  out  in  body  and  mind,  without  appetite,  and 
feeling  restless  and  jaded.     Then  a  cup  of  tea  will  often 
remove  the  feeling  of  fatigue,   enable  him  to  eat  and 
digest  his  supper,  soothe  his  nerves,  and  let  him  get  a 
good  night's  rest.     The  tea  has  not  itself  nourished  him, 
but  it  has  enabled  him  to  take  proper  nourishment,  and 
in  that  way  has  done  good. 

We  may  compare  the  safer  kinds  of  stimulants,  as  tea 
and  coffee,  to  the  "  blower"  of  a  grate.  When  a  fire  is 
burning  badly  the  blower  is  useful,  but  if  the  fire  is 
burning  well  it  only  does  harm.  It  leads  to  a  very  rapid 
using  up  of  the  coal  or  wood,  without  any  correspond- 
ing benefit,  and  does  not  itself  supply  fresh  fuel. 

4.  The  Abuse  of  Stimulants  is  chiefly  due  to  the  fact 
that  the  brief  relief  from  fatigue,  and  the  feeling  pro- 

3.  Rightly  considered  what  are  these  stimulants  ?     What  is  said  of 
their  effects  when  properly  used  ?     To  what  may  they  be  compared  ? 

4.  To  what  is  the  abuse  of  stimulants  chiefly  due  ?     What  are  the 
wrong  and  right  ways  of  regarding  them  ? 


ABUSE   OF  STIMULANTS.  93 

duced  by  them  of  being  able  to  do  more  work,  is  taken 
as  a  sign  that  they  have  really  strengthened  the  body. 
They  come  to  be  regarded  as  foods  which  may  be  taken 
safely  so  long  as  there  is  an  appetite  for  them,  and  not 
as  medicines  to  be  taken  always  with  caution. 

5.  Tea  and  Coffee. — The  amount  of  nourishment  con- 
tained in  a  cup  of  tea  or  coffee,  apart  from  the  sugar  or 
milk  put  into  it,  is  trivial.     Both  liquids  have,  however, 
a  great  power  of  making  the  brain   tranquil,  and  of  re- 
moving the  feeling  of  fatigue  or  worry.     When  taken  in 
moderate    quantity,    they  rarely    leave    injurious    after- 
effects.    Some  persons,  however,  experience  a  sensation 
of  fulness  in  the  head  after   taking   coffee,  or  are  kept 
awake  all  night  by  a  small  cup  of  it  ;   they  should   of 
course  avoid  it.     For  relieving  muscular  fatigue,  tea  or 
coffee   is    far   superior  to   any  kind   of  alcoholic  drink. 
Sportsmen  out  for  a  day's  shooting  find  a  flask   of  cold 
tea  in  the  pocket  far  more  useful  than  a  flask  of  spirits. 
Generals  who    have   commanded   troops    in    campaigns 
agree    that   a    ration   of    coffee    is  better   than    one   of 
whiskey  for  tired  soldiers.     All  commanders  of  arctic 
exploring  expeditions  have  come  to  the  conclusion  that 
the  men  bear  fatigue,  cold,  and  anxiety  better  on  tea  or 
coffee  than  when  supplied  with  rum  or  whiskey  instead. 

6.  The  Harm  done  by  Excessive  Tea-  or  Coffee-Drinking. 
—  Injurious  effects   of  excessive   tea-   or  coffee-drinking 
are   most  commonly  seen   in   those   who  are  young,  or 
who,    though    older,    lead    indolent   lives.     The    conse- 

5.  What   is   the   chief   nourishment   in   a   cup   of    tea   or   coffee  ? 
Effect   of    tea   or   coffee    on    the   body  ?      When    should    coffee   be 
avoided?     Effect    of    tea   or  coffee    on    muscular   fatigue?     Illustra- 
tions. 

6.  What  class  of  persons  are  most  liable  to  be  injured  by  tea-  and 


94  ALCOHOLIC  STIMULANTS. 

quences  of  excessive  tea-drinking  are,  dry  ness  of  the 
mouth,  loss  of  appetite,  biliousness,  a  feeling  of  sick- 
ness at  the  stomach,  nervousness  and  unreasonable 
trembling,  troubled  sleep  and  terrifying  dreams.  In 
their  full  development,  these  symptoms  are  often  met 
with  in  professional  "tea-tasters;"  but  they  are  not  un- 
frequent  in  idle  men  and  women,  who  take  no  part  or 
interest  in  the  world's  work  and  who  strive  to  keep 
themselves  from  utter  stagnation  by  drinking  strong 
tea,  morning,  noon,  and  night. 

Coffee  taken  in  excess  tends  rather  more  than  tea  to 
dilate  the  channels  through  which  blood  passes  to  the 
brain.  It  then  causes  a  feeling  of  "fulness"  in  the 
head  and  flushes  the  face.  It  is  more  apt  to  produce 
wakefulness  than  is  tea;  but  its  action  on  the  digestive 
organs  when  it  is  taken  in  excess  is  not  so  bad.  Some 
people  have  their  digestion  disturbed  by  coffee  with  milk, 
so  that  it  gives  them  hazy  vision,  dizziness,  and  head- 
ache, while  the  same  persons  experience  no  harm  from 
the  same  amount  of  coffee  without  milk. 

7.  Alcoholic  Stimulants. — Young  persons  do  not  gener- 
ally know  what  alcoholic  stimulants  are,  and  often  sup- 
pose them  to  be  only  the  various  forms  of  "strong 
spirits,"  such  as  brandy,  rum,  gin,  and  whiskey.  But  all 
wines  contain  alcohol,  and  so  do  all  beers,  cordials,  and 
even  cider,  except  when  it  is  perfectly  new.  Many  of 
the  "tonics"  so  widely  advertised,  are  also  alcoholic 
drinks,  sold  under  a  false  name.  We  have  already 

coffee-drinking?  Consequences  of  excessive  tea-drinking?  In 
whom  most  often  fully  seen?  What  other  class  of  people  are  apt  to 
exhibit  them?  How  do  the  effects  of  excessive  coffee-drinking  differ 
from  those  produced  by  tea? 

7.  Name  some  drinks  containing  alcohol.     Why  is  it  obvious  that 


ALCOHOL  AS  A    FOOD.  95 

learned  that  alcohol  tends  to  injure  seriously  the  con- 
nective tissues,  the  muscles,  and  the  skin.  We  shall 
later  learn  that  it  acts  quite  as  injuriously  on  many 
other  parts  of  the  body  ;  for  example,  the  heart  and 
the  brain  and  the  lungs.  It  is  thus  obvious  that  all 
drinks  containing  alcohol  are  dangerous,  and  the  more 
so  the  greater  the  quantity  of  alcohol  in  them.  For  the 
present,  we  will  confine  ourselves  to  the  question 
whether  alcohol  has  any  just  claim  to  be  called  a  food. 
Foods  are  useful  to  build  tissues,  to  supply  strength 
or  working  power,  or  to  maintain  our  animal  heat. 
Does  alcohol  do  any  one  of  these  ? 

8.  Is    Alcohol  a  Tissue-Forming  Food?— To   this   the 
answer  is  certainly,  no ;  so  far  at  least  as  useful  tissue 
is  concerned.     Its  consumption  often  leads  to  excessive 
and  harmful  overgrowth  of  connective  tissue   and  fat, 
but  it  does  not  lead  to  development  of  muscle  or  brain 
or  gland. 

9.  Is   Alcohol    a    Strengthening    Food? — To    this   the 
answer  is  also  no.     Alcohol  in  small,  doses  is  a  stimulant 
to  brain  and   muscle,  and  may  for  a  short   time  excite 
them  to  overwork  or  to  work  when  they  should  be  rest- 
ing.   But  as  it  nourishes  neither  of  them,  the  final  result 
is  bad.     The  brain  and  muscle  are   left  in  an   injured 
state.     As  regards  the  brain,  the  consequence  is  often 
insanity  (Chap.  XIX.).     As    regards   the  muscles,  very 
careful   experiments   have  been   made  on   soldiers  who 


alcoholic  drinks  are  dangerous?     In  deciding  the  claims  of  alcohol 
to  be  a  food,  what  properties  of  foods  must  we  recall  ? 

8.  What  is  said  of  alcohol  as  a  tissue-forming  food  ? 

9.  Is  alcohol  a  strengthening  food  ?     How  may  it   lead   to  over- 
work?    Results?     What  were  the  results    of   experiments  made  on 
soldiers  as  to  the  action  of  alcohol  on  the  muscles  ? 


96         ACTION  OP  ALCOHOL   ON  ANIMAL  HEAT. 

were  given  definite  tasks  to  accomplish.  The  result  was 
that  on  the  days  on  which  they  were  supplied  with 
spirits,  they  could  neither  use  their  muscles  as  power- 
fully, nor  for  as  long  a  time,  as  on  the  days  when  they 
got  no  alcoholic  drink. 

10.  Does  Alcohol  keep  up  the  Heat  of  the  Body  ?— To 
this  question,  also,  the  answer  is  no,  though  this  may 
seem  strange  in  view  of  the  fact  that  a  drink  is  often 
taken  "  to  warm  one  up."  The  apparent  inconsistency 
is  easily  explained.  We  have  already  learned  that  our 
feeling  of  being  warm  depends  on  the  nerves  of  the 
skin  (p.  76).  We  have  no  nerves  which  tell  us  whether 
heart  or  muscles  or  brain  are  warmer  or  cooler.  These 
inside  parts  are  always  hotter  than  the  skin,  and  if 
blood  which  has  been  made  hot  in  them,  flows  in  large 
quantity  to  the  skin,  we  feel  warmer  because  the  skin  is 
heated.  As  alcoholic  drinks  make  more  blood  flow 
through  the  skin,  they  often  make  a  man  feel  warmer. 
But  their  actual  effect  upon  the  temperature  of  the  whole 
body  is  to  decrease  it.  The  more  blood  that  flows 
through  the  skin,  the  more  heat  is  given  off  from  the 
body  to  the  air,  and  the  more  blood  so  cooled  is  sent 
back  to  the  internal  organs.  The  consequence  is  that 
alcohol  cools  the  body  as  a  whole,  though  it  may  for  a 
short  time  heat  the  skin.  That  a  large  dose  of  alcohol 
leads  to  excessive  loss  of  heat  from  the  body,  has  been 
thoroughly  proved  by  many  6bservations  on  drunken 
men,  and  by  experiments  on  the  lower  animals. 


10.  Does  alcohol  maintain  the  heat  of  the  body  ?  Why  does  a 
drink  sometimes  make  a  person  feel  warmer?  What  is  the  real 
effect  of  alcoholic  drinks  on  the  temperature  of  the  body?  How  has 
it  been  proved  ? 


ALCOHOL  AS  A   MEDICINE.  97 

11.  Alcohol  is  a  Medicine. — In  many  diseases  the  body 
needs  rousing  to  make  a  special  effort,  and  the  physician 
has  to  order  an  alcoholic  stimulant,  or  some  substance 
which  acts  on  the  body  in  a  like  way.  Not  merely  is  it 
a  powerful  stimulant,  but  in  moderate  doses  it  checks 
for  a  time  the  oxidations  of  the  body,  and  thus  dimin- 
ishes the  wasting  of  its  organs.  This  only  harms  a 
healthy  well-nourished  person,  but  may  often  be  use- 
ful in  impaired  health.  In  fact,  alcohol  is  a  medicine, 
and  often  a  very  valuable  one.  It  may  be  classed  with 
strychnine,  arsenic,  opium,  and  other  drugs,  which  are 
useful  in  various  impaired  states  of  health,  but  so  dan- 
gerous that  they  should  only  be  taken  on  the  advice  of 
a  doctor,  and  in  the  exact  manner  and  quantity  ordered 
by  him. 

Probably  few  physicians  would  be  willing  to  omit 
alcohol  from  the  list  of  remedies;  but  many  patients 
have  acquired  drinking  habits  from  first  taking  an  alco- 
holic stimulant  on  the  "doctor's  advice."  Many  medical 
men,  for  this  reason,  prescribe  it  in  some  disguised  form; 
and  this  is  the  better  plan. 

ii.  When  may  it  become  necessary  to  take  alcohol  internally? 
With  what  poisonous  drugs  classed  ?  Precautions  to  be  used? 


CHAPTER   X. 
DIGESTION. 

1.  Introductory. — We  learned  almost  at  the  outset  of 
our  anatomical  study,  that  the  alimentary  canal  is  but 
a  tube  (Fig.    i)  which,  beginning  at   the    mouth,  runs 
through    the    neck,   chest,   and  abdomen;   and   ends  by 
opening  again  on  the  outside  at  the  lower  part  of  the 
trunk  of  the  body.     We   now  have  further  to  observe 
that  it  is  wide  in  some  parts,  like  the  stomach  and  large 
intestine  (all   to  be  presently  described),  and  narrow  in 
others,  like  the   gullet  and   small  intestine,  which  will 
also  be  presently  described;  some  parts  of  it  are  straight 
and  others  coiled;  but  it  has  no  branches  which  reach 
out  into  the  arms  or  legs  or  brain.     Nevertheless,  after 
a  good  dinner  we  feel  no  doubt  that  what  we  have  eaten 
is  going  to  strengthen  our  limbs  and  every  other  part  of 
the  body.     To  accomplish  this,  the  nourishing  portions 
of  the  food  must  get  through  the  walls  of  the  alimen- 
tary canal,  and  then  be  carried  to  all  the  organs. 

2.  Digestion  — The  first  important  thing  that  happens 
to  our  food  inside  the  alimentary  canal,  by  way  of  pre- 
paring it  to  reach  distant  organs,  is  that  its  solid  parts, 
or  at  least  those  of  them  which  are  nourishing,  are  dis- 

1.  How  do  the  various  parts  of  the  alimentary  canal  differ  ?     What 
must  happen  in  order  that  food  may  nourish  all  parts  of  the  body  ? 

2.  What  is  the  first  important  work  inside  the  alimentary  canal  to 


ABSORPTION.  99 

solved.  This  is  brought  about  by  the  action  of  peculiar 
liquids  made  inside  the  body,  and  poured  into  the  mouth, 
stomach,  or  intestines.  The  process  of  getting  all  the 
valuable  part  of  the  things  which  we  have  eaten,  into  a 
liquid  state,  is  known  as  digestion. 

•'  3.  Absorption. — -The  second  step  is  to  get  this  nourish- 
ing liquid  into  the  blood.  As  it  slowly  passes  along  the 
alimentary  tube  it  is  gradually  soaked  up  or  absorbed  by 
the  walls  of  the  latter,  as  if  they  were  lined  with  blotting- 
paper,  and  either  mixed  at  once  with  the  blood  which 
flows  in  them;  or,  first,  with  another  liquid,  the  lymph, 
which  is  afterwards  poured  into  the  blood.  The  taking 
up  of  digested  food  by  the  lining  of  the  alimentary 
canal,  is  known  as  absorption. 

4.  The  Alimentary  Canal  is  about  thirty  feet  in  length, 
much  the  longest  portion  of  it  being  contained  in  the 
abdomen.  At  it^lbeginning  (Fig.  24)  it  is  tolerably  wide 
and  forms  the  mouth  and  throat  cavities.  In  the  neck  and 
chest,  it  has  the  form  of  a  narrow,  nearly  straight  tube, 
the  gullet  or  oesophagus.  The  lower  end  of  the  gullet 
passes  through  the  diaphragm  and  then  almost  immedi- 
ately opens  into  the  much  wider  stomach  (Fig.  32).  The 
stomach  is  followed  by  the  narrow  greatly  coiled  small 
intestine;  and  this  in  turn  opens  into  the  large  intestine, 
which  is  the  last  portion  of  the  alimentary  canal. 

prepare  food  for  nourishing  the  body  ?  How  brought  about  ?  What 
is  the  process  called  ? 

3.  What  is  the  second  step  in  digestion  ?     How  does  the  nourishing 
liquid  get  into  the  blood  ?     What  is  lymph  ?     What  is  this  process  of 
taking  up  digested  food  called  ? 

4.  How  long  is  the  alimentary  canal?     What  easily  contains  the 
longest  portion  of   it?     What    is  the    gullet?     Where  does    it    end? 
What  follows  the  stomach  ?     What  is  the  large  intestine  ? 


100 


MUCOUS  MEMBRANE. 


5.  The  Lining  of  the  Alimentary  Canal  is  a  soft,  red, 

moist  kind  of  skin,  named 
a  mucous  membrane.  You  can 
easily  see  part  of  it  on  ex- 
amining the  inside  of  your 
mouth  with  the  help  of  a 
looking-glass.  This  mucous 
membrane  has  two  func- 
tions, secretion  and  absorption. 
Imbedded  in  it  are  thou- 
sands of  tiny  glands  (p.  65), 
which,  instead  of  making 
perspiration  or  oily  matter, 
like  the  skin-glands,  pour 
out  very  different  liquids, 
which  aid  in  swallowing  and 
digesting. 

6,  The  t  Month-Chamber 
(Fig.  24)  opens  in  front  be- 
tween the  lips,  and  behind 
into  the  throat-chamber  or 
pharynx.  It  is  bounded  on 
the  sides  by  the  cheeks,  be- 
p^hftej  low  b7  the  tongue,  above  by 

m,  the  sphenoid   bone  on  the  base  of  .->        ,     /    ,         r^,       £ 

the  skull;  «,  the  fore  part  of  the  skull-  tne/lWiWfc,       1  he  front  portion 

cavity;  o,p,  q,  the  turbinate  bones  of  .     . 

the  outer  side  of  the  left  nostril-cham-  OI  trie  palate, /,  Separates  the 

mouth  from  'the    nose,  and 

is  supported  by  bone.     This  portion  is  named  the  hard 
palate.     The  posterior   portion  of  the  palate,  /,  is  soft 

5.  What  is  the  lining  of  the  alimentary  canal  ?     Where  can  you 
easily  see  it  ?     What  are  its  functions?     How  does  it  aid  in  swallow- 


ing  and  digesting  ? 

6.   Describe  the  mouth-chamber. 


The  hard  palate.     The  soft  pal- 


THE    TEETH.  IOI 

and  contains  no  bone.  It  forms  a  curtain  between  the 
mouth  and  pharynx;  there  hangs  down  from  its  lower 
border  a  soft  fleshy  projection,  named  the  uvula,  gener- 
ally miscalled  the  palate.  If  the  mouth  be  held  wide 
open  in  front  of  a  mirror,  the  uvula  can  be  easily  seen, 
and  also  the  opening,  between  the  soft  palate  and  the 
root  of  the  tongue,  which  leads  into  the  pharynx.  This 
opening  is  named  the  isthmus  of  the  fauces.  On  its  sides 
are  the  tonsils. 

7.  The  Teeth  stand  almost  alone  among  the  organs 
of  the  body,  in   the  fact  that  when  broken  or  seriously 
injured    or    much    worn,    they   are    not    repaired.      To 
do  their  duty  they  must  be   very  hard,  and    they  gain 
this    hardness    by  being    so   largely    made  of    mineral 
matter  that  their  living  animal  part  is   not  present   in 
sufficient  quantity  to  rebuild  them  when  they  are  broken 
or  decayed.     During  life  two  sets  of  teeth  grow.     The 
first,  named  the  milk-teeth,  are  developed  and  shed  dur- 
ing childhood.     The    second  set,    named  the  permanent 
teeth,  follow  the   milk-teeth.     If  they  are  lost,  we  must 
go  to  the  dentist,  for  no  others  will  grow  to  take  their 
places. 

8.  The  Forms  and  Uses  of  Different  Teeth,  —  Every  tooth 
consists  of  a   crown,  the    part  which    projects    into   the 
mouth;  of  a  narrower  neck,  surrounded  by  the  gums; 
and  of  one  or  more  roots  or  fangs,  tightly  fitted  into  pits 
(called  sockets)  in  the  edges  of  the  upper  and  lower  j 


ate.     What  is  the  opening  seen  between  the  soft  palate  and  root  of 
the  tongue  ?    The  organs  on  each  side  ? 

7.  How  do  the  teeth  differ  from  most  other  organs  as  to  repair  ? 
How  is  this  accounted  for  ?     What  is  said  of  the  first  set  of  teeth  ? 
The  second? 

8.  Of  what  parts  does  a  tooth  consist  ?   Give  names  of  the  different 
teeth.     Describe  the  incisors.     Canines.     Molars.     Bicuspids, 


102 


THE    TEETH. 


bones.  On  account  of  differences  in  the  shape  of  their 
crowns,  and  in  their  uses,  the  teeth  are  divided  into  in- 
cisors, canines,  bicuspids,  and  molars.  The  incisors  (Fig.  25) 
have  sharp  chisel-shaped  edges  and  are  adapted  for  cut- 
ting our  food.  The  canines  (Fig.  26)  or  eye-teeth  are 


FIG.  25. 


FIG.  26. 


FIG.  27. 


FIG.  28. 


FIG.  25. — An  incisor  tooth. 

FIG.  26. — A  canine  or  eye  tooth. 

FIG.  27. — A  bicuspid  tooth  seen  from  its  outer  side  ;  the  inner  cusp  is  accord- 
not  visible. 
IG.  28.— A  molar  tooth. 


pointed  and  serve  the  same  purpose:  they  are  very  long 
and  sharp  in  dogs  and  cats,  and  are  useful  to  these  ani- 
mals in  holding  their  prey.  The  molars  (Fig.  28)  have 
broad  rough  ends  to  their  crowns  and  are  suited  to  grind 
and  crush.  The  bicuspids  (Fig.  27)  are  like  the  molars 
but  not  so  large. 

9.  Arrangement  of  the  Teeth  in  the  Jaws.— In  the 
milk-set,  there  are  twenty  teeth,  ten  in  each  jaw.  Begin- 
ning in  the  middle  line  and  going  back,  we  find  in  order, 
on  each  side,  two  incisors,  one  canine,  two  molars. 

The  permanent  teeth  number  sixteen  in  each  jaw. 
Beginning  at  the  middle  line,  we  find  successively  two 
incisors,  one  canine,  two  bicuspids,  and  three  molars,  in 
each  half  of  each  jaw.  The  incisors  and  canines  take 
the  places  of  the  milk-teeth  of  the  same  names.  The 

9.  Arrangement  of  milk-teeth.  Of  permanent  teeth.  Which  ones 
are  added  as  the  jaw  grows  larger  ?  What  of  the  wisdom-teeth  ? 


PERMANENT    TEETH. 


103 


bicuspids   supplant   the  milk-molars.      The   permanent 
molars  are  added  as  the  jaw  grows  larger;  the  hindmost 


FIG.  29. — Section  through  a  tooth  still  imbedded  in  its  socket,    i,  enamel;  2,  den- 
tine; 3,  cement;  4,  the  gum;  5,  the  bone  of  the  lower  jaw;  c,  the  pulp-cavity. 

ones,  often  named  the  wisdom-teeth,  do  not  appear  until 
about  the  twentieth  year  of  life. 


104  STRUCTURE   OF  A    TOOTH. 

10.  The  Pulp  of  a  Tooth.— If  a  tooth  be  broken  open,  a 
cavity  (c,  Fig.  29)  will  be  found  inside  it.     It  is  named 
the  pulp-cavity,  and  during  life  is  filled  with  a  soft  red 
very  sensitive  core,  full  of  blood  and  nerves,  named  the 
pulp.    At  the  tip  of  the  fang,  or  of  each  fang,  if  the  tooth 
has  more  than  one,  is  a  small  aperture  through  which 
the  nerves  and  blood  enter.      The  pulp  nourishes  the 
tooth;  on  account  of  the   nerves   in  it,   it  gives   rise   to 
great  pain  when  exposed  or  inflamed.     When  a  dentist 
speaks  of  destroying  or  removing  the  "  nerve"  of  a  tooth, 
he  means  the  pulp. 

11.  The  Hard  Parts  of  a  Tooth  (Fig.  29)  are  made  of 
three  different  materials.     Surrounding  the  pulp-cavity 
is  dentine  or  ivory:  an  elephant's  tusk  is  made  of  dentine. 
Covering  the  ivory  in  the  crown,  is  enamel,  the  tissue  of 
the  body  which  contains  least  animal  matter.     It  is  so 
hard  that  it  will  strike  a  spark  with  steel.     Covering  the 
dentine  in  the  fang,  is  what  has  been  named  the  cement; 
it  is  but  a  thin  layer  of  bone  under  another  name.     The 
dentine    is  harder    than  bone,  though    not   so   hard    as 
enamel. 

12.  Hygiene  of  the  Teeth. — A  great  portion  of  the  hard 
parts  of  a  tooth  consists  of  a  very  hard  kind   of  chalk, 
and  like  chalk  it  is  readily  eaten  away,  or  dissolved,  by 
sour  or   acid  liquids.     The  mouth   should   therefore  be 
well  washed  after  eating  lemons  or  other  sour  things: 
and  acid  medicines  should  be  sucked  through  a  glass 

10.  What  is  the  pulp  of  the  tooth  ?     How  do  blood  and  nerves  get 
into  the  pulp  ?     Use  of  the  pulp.     Why  called  the  nerve  ? 

11.  What    is  dentine?      Enamel?      Cement?     How   does   dentine 
compare  with  enamel  ? 

12.  What  is  the  effect  of  acids  on  the  teeth?     What  precautions  are 
therefore  necessary  for  their  preservation  ?     How  may  acids  be  made 
in  the  mouth  ?     What  is  sajd  of  decay  of  the  teeth  ? 


THE    TONGUE,  1 05 

tube,  and  swallowed  after  as  little  contact  with  the  teeth 
as  may  be  possible. 

Many  foods  if  kept  in  the  warm  moist  mouth,  decom- 
pose and  give  rise  to  acids:  the  teeth  should  therefore 
be  thoroughly  cleansed  twice  daily,  with  a  soft  tooth- 
brush and  tepid  water.  Finely  powdered  chalk  or  a 
little  soap  may  be  placed  on  the  brush  with  advantage, 
as  they  counteract  any  acids  which  may  be  present.  The 
enamel  is  not  so  easily  attacked  as  the  deeper  parts  of  a 
tooth;  but  once  the  enamel  is  injured,  the  dentine  is  apt 
to  decay  rapidly.  Small  cavities  in  the  enamel  are  not 
easily  discovered  unless  they  are  on  the  outer  side  of  the 
tooth.  Remnants  of  food  collect  in  them  and,  making 
acids,  rapidly  eat  away  the  tooth.  The  teeth  should 
therefore  be  thoroughly  examined  by  a  dentist  two  or 
three  times  a  year,  and  all  cavities  filled. 

13.  The  Tongue  (Fig.  60)  is  endowed  not  only  with  a 
delicate  sense  of  touch,  but  is   the  chief  organ  of   the 
sense  of  taste.     Being  highly  muscular  and  very  mov- 
able, it  also  plays  a  great  part  in  guiding  food  inside  the 
mouth,  so  as   to   push   it  between  the  teeth   until  it  is 
properly   chewed,    and    then    to   drive    it    on    into    the 
pharynx  to  be  swallowed.    As  an  organ  of  taste,  we  shall 
study  the  tongue  later  (Chap.  XXL). 

14.  What  a  "Furred  Tongue"  Indicates.— In  health  the 
mucous  membrane  covering  the  tongue  is  moist,  covered 
by  little  "  fur"  and,  in  childhood,  of  a  bright  red  color. 
In  adults,  the  natural  color  of  the  tongue  is  less  red,  ex- 
cept around  the  edges  and  at  the  tip.     When  any  part  of 

13.  Of  what  is  the  tongue  the  chief  organ  ?    What  muscular  work 
does  it  perform  ? 

14.  What  is  said  of  the  covering  of  the  tongue ?     Color?     Indica- 
tions of  disordered  digestion  ? 


IO6  SALIVARY  GLANDS. 

the  alimentary  canal  farther  on  is  out  of  order,  the 
tongue  is  apt  to  be  covered  with  a  thick  yellowish  coat- 
ing, and  there  is  a  "bad  taste"  in  the  mouth.  This  may 
in  most  cases  be  taken  as  a  sign  that  there  is  something 
wrong  with  the  stomach. 

15.  The  Salivary  Glands. — The  liquid  which  moistens 
the  mouth  is  named  saliva.     It  consists  of  a  slimy  fluid, 
named  mucus,  made,  or  secreted,  as  we  say  in  physiology, 
by  the  tiny  glands  of   the    mucous    membrane,    mixed 
with  a  more  watery  secretion   made  by  three  pairs  of 
salivary  glands.     These  glands  lie  outside  the  mouth,  but 
pour  their  secretion  into  it  through  tubes  or  ducts.    Two 
of  the  salivary  glands  are  placed  in  front  of  the  ears  ; 
their  ducts  open  on   the    inside   of   the  cheek  opposite 
the  second  upper  molar  tooth.     In    the  disease  known 
as  mumps  they  become  greatly  swollen.     The  other  sali- 
vary glands  lie   between  the  halves   of  the  lower  jaw- 
bone.    Their   ducts    open  into  the   mouth  beneath  the 
tongue. 

16.  The  Uses  of  Saliva  are  several,     (i)  It  keeps  the 
mouth   moist  and    enables    us    to   speak  with    comfort. 
This  is  well  illustrated  by  the  trouble  from  dryness  of 
the    mouth  experienced  by  many  young  orators  when 
they  first  try  to  speak  in  public.     The  dryness  is  due 
to  the    fact    that  nervous   excitement  for  a  time   para- 
lyzes the  salivary  glands  and  stops  their  secretion.     (2) 
The  saliva  enables  us  to  swallow  dry  food.     A  cracker 
when  chewed  would  give  rise  merely  to  a  heap  of  dust, 

15.  What   is   saliva?     How   made?     Describe  the  position  of  the 
salivary   glands.     Where  do  the  ducts  of  each  pair  open  ? 

16.  What   is    the    first   use   of   saliva?      Illustrate.      The    second? 
Illustrate.     The  third?     Illustrate.     The  fourth? 


USES  OF  SALIVA.  IO7 

impossible  to  swallow,  if  it  were  not  moistened.  This 
fact  was  made  use  of  in  the  former  East  Indian  rice- 
ordeal.  All  suspected  persons  were  brought  together 
and  given  parched  rice  to  eat.  The  guilty  individual, 
believing  that  his  gods  would  bring  his  crime  to  light, 
usually  had  his  salivary  glands  paralyzed  by  fear,  and 
so  could  not  secrete  enough  saliva  to  enable  him  to 
swallow  the  dry  rice ;  while  those  with  clear  con- 
sciences had  no  difficulty.  (3)  Saliva,  by  dissolving 
many  solid  substances,  enables  us  to  taste  them. 
Things  in  the  solid  state  cannot  be  tasted,  as  you  may 
easily  discover  by  wiping  your  tongue  dry  and  placing 
a  piece  of  lump-sugar  on  it.  Until  a  little  moisture  has 
come  out  and  dissolved  some  of  the  sugar,  no  taste  will 
be  perceived.  (4)  Saliva  turns  starch,  which  is  not  itself 
nourishing,  into  sugar,  which  is. 

17.  Digestion  in  the  Mouth. — By  means  of  the  teeth,  the 
solid   parts  of   our  food  are  cut  and  crushed.     At   the 
same  time,  they  are  softened  and  made  ready  for  swal- 
lowing by  mixture   with  the  saliva.     Saliva  also  alters 
some  nourishing  substances  in  the  food,  and  so  changes 
them  that  instead  of  being  insoluble  they  become  readily 
soluble. 

18.  The  Action  of  Saliva  upon   Starch. — Raw   starch 
may  be  mixed  with  water,  but  will  not  dissolve  in  it. 
After  a  while,  all  the  starch  settles  down  from   such  a 
mixture.     When  starch   is  boiled  in  water,  it  swells  up 
very  much   and  mixes   more  thoroughly  with   the  water 
than  raw  starch  does,  but  still  it  does  not  dissolve.     If 

17.  How  is  digestion  carried  on  in  the  mouth?     What  are  the  uses 
of  saliva  ? 

18.  What    happens    when    starch    is    mixed    with    water?      When 
boiled  ?     What  happens  if  you  strain  a  solution  of  sugar  and  water  ? 


1 08  MA  S  TIC  A  T1ON. 

you  dissolve  some  salt  or  sugar  in  water,  and  pour  the 
solution  into  a  bag  made  of  three  or  four  thicknesses 
of  very  fine  muslin,  the  salt  or  sugar  will  come  through 
just  as  freely  as  the  water.  But  if  you  try  the  same 
experiment  with  boiled  starch,  you  will  find  that  the 
water  comes  through,  but  leaves  most  of  the  starch 
behind  it  inside  the  bag.  The  tiny  openings  or  pores 
of  the  mucous  membrane  lining  the  alimentary  canal, 
through  which  the  dissolved  food  has  to  pass  when  it  is 
absorbed  into  the  blood,  are  far  smaller  than  the  holes  in 
the  finest  muslin;  and  starch,  whether  raw  or  boiled,  could 
not  get  through  them.  The  saliva  turns  starch  into  sugar, 
which  dissolves  rapidly  and  is  very  easily  absorbed  by 
the  mucous  membrane.  In  this  way  bread  and  corn 
and  arrowroot  and  many  other  articles  of  diet  which 
contain  much  starch  (p.  87)  are  enabled  to  nourish  our 
bodies. 

19.  Why  Food  should  be  well  Masticated. — Some  per- 
sons eat  as  if  all  that  their  teeth  and  mouth  had  to  do 
was  to  bite  and  swallow  :  they  seem  to  believe  that  their 
stomachs  are  like  the  gizzard  of  a  bird,  constructed  to 
crush  and  grind.  Nature  having  provided  man  with 
teeth,  has  given  him  no  gizzard  :  the  human  stomach 
will  certainly  get  out  of  order  if  it  is  frequently  called 
upon  to  do  the  work  of  one.  Our  molar  teeth  are  so 


Of  starch  ?  How  may  the  pores  of  the  mucous  membrane  of  the 
alimentary  canal  be  compared  to  muslin  ?  How  does  the  action  of 
saliva  enable  starch  to  get  through  these  pores  ?  Why  could  we  not 
digest  bread,  corn,  arrowroot,  and  like  food  without  saliva? 

19.  What  duty  besides  biting  and  swallowing  have  the  teeth  in 
connection  with  digestion  ?  Where  do  fowls  crush  hard  food  ?  What 
is  the  consequence  if  we  eat  as  if  we  had  gizzards  ?  What  is  the  evi- 
dent duty  of  our  molars  ?  How  does  chewing  affect  the  salivary 
glands  ? 


USE   OF  MASTICATION.  IOQ 

clearly  fitted  to  break  up  our  food  into  small  pieces  that 
there  can  be  no  doubt  as  to  what  their  use  is. 

The  chewing  or  mastication  of  food  also  causes  a 
greater  flow  of  saliva.  When  we  are  not  eating,  the 
salivary  glands  secrete  little;  but  as  soon  as  we  com- 
mence to  chew,  they  begin  to  be  more  active.  If  food 
be  swallowed  hastily,  it  is  not  mixed  with  sufficient 
saliva,  and  in  consequence,  its  starchy  parts  are  imper- 
fectly digested. 


CHAPTER  XI. 
DIGESTION,  CONCLUDED. 

1.  The  Pharynx  (Fig.  30)  is  a  muscular  bag  lined  by 
mucous  membrane;  it  opens  at  its  lower  end  into  the 
gullet,  b.     Not  only  our  food,  but  also  the  air  which  we 
breathe,  has   to   pass   through   the  pharynx,  for  into  its 
upper   portion,   above    the   level   of   the   palate, /,/,  the 
inner  ends   of  the   nostril-chambers   open.      Under  the 
soft  palate,/,  is  the  aperture  through  which  food  is  sent 
from  the  mouth;  and,  lower  still,  another  opening,  be- 
hind the  root  of  the  tongue,  through   which   air  enters 
the  passage,  r,  which  transmits  it  to  the  lungs. 

2.  Swallowing  or  Deglutition  is  the  process  of  sending 
food  or  drink  from  the    mouth    to    the    stomach.     The 
liquid,  or  the  mass  of  chewed  solid  food,  is  collected  on 
the  upper  surface  of  the   tongue,  and  then  pushed   into 
the  pharynx.     As   soon    as    it    has    left    the    mouth,  the 
opening  between  mouth  and  pharynx  is  closed,  to  pre- 
vent  its  return.     At  the  same    instant  the   soft   palate 
is  raised,    so   as    to  separate  the  upper  from  the  lower 
portion  of  the  pharynx:    in    this  way  the   food   is  pre- 
vented  from  getting  into  the  nose.     The  lid,  e,  named 

1.  What  is  the  pharynx?    What  besides  food  passes  through  it? 
What  opens  into  it  above  the   palate  ?     Below  ?     Behind  the  root  of 
the  tongue? 

2.  What  is  deglutition?     How  is  food  sent  from  the  mouth  to  the 
pharynx?     How  is  its  return  prevented?     How  is  it  kept  from  getting 


SWALLOWING. 


Ill 


the  epiglottis,  which  overhangs  the  aperture  leading  to 
the  windpipe,  c,  is  also  shut 
down.  Therefore,  when  the 
muscles  of  the  pharynx  con- 
tract and  press  on  the  food, 
the  only  way  it  can  go  is 
into  the  gullet,  b.  Occasion- 
ally a  morsel  '*  goes  the 
wrong  way,"  and  gets  into 
the  air-passage,  causing  a  fit 
of  coughing  which  drives  it 
back  into  the  pharynx.  The 
things  which  we  swallow  are 
hurried  through  the  pha- 
rynx very  fast,  so  as  to  get 
it  clear,  and  enable  us  to 
breathe  again. 

3.  The  Passage  of  Food  and 
Drink  along  the  Gullet  or  oeso- 
phagus, is  slow.  A  mouthful 
of  food  or  drink  when  it  has 

«.         j   4.u  i,  j  gullet  and  larynx,  as  exposed  by  a  sec- 

entered  the  OeSOphagUS  does      fion,  a  little  to  the  left  of  the  middle 
,    ,  ,  ^.  ,  of  the  head,    a,  vertebral  column;  6, 

not  drop  dOWn  that  tube  mtO      gullet;  <r,  windpipe;  d,  larynx;  e,  epi- 
,  glottis;  f.   soft  palate;  g,   opening  of 

the      Stomach,     like     a     brick      Eustachian  tube;  the  letters  e,f,g  are 

placed    in  the  pharynx;  k,  tongue;    /, 

tailing  down  a  Chimney,  but      hard  palate;  m,  the  sphenoid  bone  on 

the  base  of  the  skull;  «,  the  fore  part 

is     Seized     by     the     muscular     of    the  cranial     cavity;    o,  p*  q,  the 
J  turbinate  bones  of  the  outer  side  of  the 

rings  in   the    COat  of  the  gul-      left  nostril-chamber. 

let,  which  contract  one  after  another  and  push  it  along. 

into  the  nose  ?  Into  the  windpipe  ?  What  does  it  enter  when  forced 
out  of  the  pharynx  ?  What  is  meant  when  a  morsel  of  food  is  said  to 
have  gone  the  wrong  way  ?  Why  is  food  sent  quickly  through  the 
pharynx? 

3.   How  do  food  and  drink  pass  along  the  gullet  ?     Illustrate. 


112  THE   STOMACH. 

For  this  reason,  horses  and  many  other  animals  are  able 
to  swallow,  although  they  usually  eat  with  their  mouths 
much  lower  than  their  stomachs;  and  jugglers  are  able 
to  drink  a  glass  of  water  while  standing  on  the  head. 

4.  The  Stomach  (Fig.  31)  is  a  dilated  portion  of  the 
alimentary  canal,  which  lies  at  the  lower  end  of  the  oeso- 
phagus, in  the  upper  part  of  the  abdomen,  rather  more 
on  the  left  than  the  right  side  of  the  body  (see  Fig.  2). 
Outside  its  lining  mucous  membrane,  is  a  thick  muscular 
coat. 


FIG.  31.— The  stomach  viewed  from  the  front,  rf,  lower  end  of  the  gullet;  a, 
position  of  the  cardiac  aperture;  3,  the  fundus;  c,  the  pylorus;  e,  the  first  part  of 
the  small  intestine. 

The  gullet,  d,  opens  into  the  upper  side  of  the  stomach 
by  an  aperture  named  the  cardiac  orifice.  The  right  end  of 
the  stomach  gradually  narrows  to  the  commencement  of 
the  small  intestine,  e.  The  place,  c,  where  stomach  and 
intestine  meet  is  named  the  pylorus,  and  the  opening 
which  places  their  cavities  in  communication  is  \\\tpyloric 
orifice.  When  moderately  distended,  the  stomach  con- 
tains about  three  pints. 

4.  Position  of  the  stomach  ?  What  is  outside  its  mucous  mem- 
brane ?  How  and  where  does  the  gullet  enter  it?  How  does  the 
stomach  join  the  small  intestines  ?  What  is  the  pylorus  ?  The  py- 
loric  orifice  ?  Capacity  of  the  stomach  ? 


DIGESTION  IN   THE    STOMACH.  113 

5.  The  Gastric  Juice. — The  mucous  membrane  of  the 
stomach  is  almost  entirely  made  up  of  thousands  of  tiny 
glands,  placed  side  by  side  nearly  as  close  as  they  can 
be   packed.     The    liquid    which    these   glands    make    is 
poured    into  the  stomach,  and  is  known  as    the  gastric 
iuice.    If  you  imagine  a  piece  of  honeycomb  reduced  very 
much  in  size,  and  that  its  cells  answer  to  the  glands,  you 
will  have  a  fair  idea  of  how  the  glands  lie  in  the  mucous 
membrane   of   the   stomach.     To   complete    the  resem- 
blance, each  cell  would  have  to  be  open  at  one  end,  and 
through  this  opening  to  pour  its  honey  on  the  surface  of 
the  comb,  and   to  keep  on  making  honey  to  take  the 
place  of  that  it  had  emptied  out.    The  liquid,  too,  would 
have  to  be  much  thinner  than  honey,  and  sour  or  acid, 
instead  of  sweet. 

6.  Digestion    in    the    Stomach.  —  When    the    healthy 
stomach  is  empty,  its  mucous  membrane  is  something 
like  grayish-pink  velvet  and  its  glands  make  hardly  any 
gastric  juice.      As  soon  as  food  is  swallowed,  a  great 
deal  of  blood  flows  to  the  mucous  membrane,  and  it  be- 
comes  red.     At  the  same  time,  its  glands  secrete  abun- 
dantly, and,   all  over  the  surface,  gastric  juice  trickles 
out,  like  sweat  on  the  skin  of  a  person  perspiring  pro- 
fusely.    These  facts  were  first  observed  many  years  ago, 
on  a  Canadian  hunter,  named  Alexis  St.  Martin,  who,  as 
a  result  of  a  gunshot  wound,  had  a  small  opening  from 
the  surface  of  his  abdomen  into  his  stomach.     Through 
this  opening,  what  was  going  on  inside  his  stomach  could 

5.  Of  what  is  the  mucous  membrane  of  the  stomach  chiefly  made 
up  ?     What  is  the  gastric  juice  ?     Illustrate. 

6.  What  is  the  state  of  the  stomach  when  empty  ?     After  swallow- 
ing  food  ?     How  were  these    facts    first    observed  ?     What    are  the 
chief  foods  acted  on  in  the  stomach  ?     How  are  they  changed  ? 


114  THE  MUSCLES  OF   THE   STOMACH. 

be  watched.  Since  then  the  careful  observations  made 
by  his  physician  have  been  confirmed  by  the  study  of 
several  similar  cases. 

The  chief  kinds  of  foods  acted  on  in  the  stomach,  are 
of  albuminous  nature  (p.  85),  lean  meat,  white  of  egg, 
cheese,  the  gluten  of  bread,  and  so  forth.  They  are 
turned  into  a  condition  in  which  they  can  be  dissolved 
and  absorbed. 

7.  The  Muscular  Coat  of  the  Stomach  (Fig.  19)  per- 
forms two  duties:  first,  it  thoroughly  mixes  our  food 
with  the  gastric  juice;  and  next,  it  drives  it  on  into  the 
intestine.  The  pyloric  orifice  (c,  Fig.  31)  is  narrow, 
and  surrounding  it  is  a  thick  ring  of  muscle  which 
keeps  the  passage  closed,  for  an  hour  or  more  after  eat- 
ing. During  this  time,  the  muscles  of  the  stomach  con- 
tracting, now  in  one  direction  and  now  in  another,  keep 
its  contents  in  constant  motion  and  bring  every  part  of 
the  food  into  contact  with  the  gastric  juice. 

When  the  digestive  process  has  gone  on  until  some 
food  is  ready  to  enter  the  intestine,  the  muscle  around 
the  pylorus  relaxes  a  little  from  time  to  time;  thus 
some  liquified  food  is  passed  through  the  opening. 
When  all  the  things  which  can  be  dissolved  in  the 
stomach  have  been  passed  on,  the  pyloric  orifice  opens 
wider  and  lets  solid  indigestible  things  get  through. 
In  this  way  buttons,  coins,  cherry-stones,  and  other  such 
things  which  may  have  been  swallowed  reach  the 


7.  What  are  the  duties  of  the  muscular  coat  of  the  stomach  ? 
What  surrounds  the  pyloric  orifice  ?  Its  use  ?  What  happens  while 
the  passage  is  closed  ?  What  occurs  when  some  food  has  been  pre- 
pared to  enter  the  intestine  ?  What  occurs  when  the  stomach  has 
done  all  it  can  towards  digesting  its  contents  ?  How  soon  after  an 
ordinary  meal  is  the  stomach  empty  ? 


THE   PYLORUS.  115 

bowels,  to  travel  through  them  and,  in  fortunate  cases, 
be  sent  out  of  the  body,  along  with  indigestible  portions 
of  the  food.  In  health  the  stomach  is  completely  emp- 


FIG.  32.— The  abdominal  portions  of  the  alimentary  canal.  A,  stomach;  C,  lower 
end  of  gullet  ;  P,  pylorus  ;  Z>,  y,  /,  portions  of  the  small  intestine,  named  re- 
spectively duodenum,  jejunum,  and  ileum  ;  CC,  AC,  TC,  DC,  SF,  /?,  portions  of 
the  large  intestine,  named  respectively  the  caecum,  ascending  colon,  transverse 
colon,  descending  colon,  sigmoid  flexure,  and  rectum. 

tied  in  from  two  and  a  half  to  three  and  a  half  hours 
after  an  ordinary  meal. 

8.  The  Small  Intestine  (Z>,  /,  /,  Fig.  32),    commenc- 

8.   Commencement,  course,  and  ending  of  small  intestine  ?     Length 


Il6  THE  LIVER. 

ing  at  the  pylorus,  ends  after  many  windings,  by  join- 
ing the  large.  In  an  adult  it  is  about  twenty  feet  long 
and  an  inch  and  a  half  wide.  Imbedded  in  its  mucous 
membrane,  are  myriads  of  tiny  glands,  much  like  those  of 
the  stomach  in  shape  and  arrangement,  but  preparing 
a  digestive  liquid  very  different  from  the  gastric  juice. 
This  liquid  is  mixed  with  the  food,  as  it  is  slowly 
driven  along  by  the  muscles  in  the  coat  of  the  intestine. 
In  addition,  two  large  glands,  the  liver  and  the  pancreas, 
pour  their  secretion  into  the  small  intestine  near  its 
upper  end. 

9.  The  Liver  is  by  far  the  largest  gland  in  the  body. 
It  is  placed  in  the  upper  part  of  the  abdomen  on  the 
right  side  (Fig.  2,  /^,  /<?'),  close  under  the  diaphragm. 
The  secretion  of  the  liver  is  named  bile  or  gall.  When 
no  food  is  being  digested  in  the  intestine,  the  bile  col- 
lects in  a  pear-shaped  bag,  the  gall-bladder,  which  lies 
under  the  liver.  As  soon  as  food  is  sent  on  from  the 
stomach,  the  gall-bladder  empties  bile  upon  it  through  a 
tube  or  duct  which  opens  into  the  intestine  about  op- 
posite D,  Fig.  32. 

Fresh  human  bile  is  a  yellow-brown  liquid.  It  is  much 
like  weak  lye  in  some  of  its  properties;  and  ox-bile  or 
ox-gall  is  occasionally  used  by  housekeepers  instead  of 
lye,  for  cleansing  purposes,  to  dissolve  and  remove 
grease-spots.  One  chief  use  of  bile  is  to  aid  in  digest- 
ing the  oily  and  fatty  parts  of  our  food. 

and  width  1  The  glands  of  its  mucous  membrane  1  Their  secre- 
tion 7  What  other  glands  pour  secretion  into  the  small  intestine  1 
Where  1 

9.  What  is  said  of  the  liver  7  Its  position  1  Name  of  its  secre- 
tion ?  Where  stored  when  not  needed?  How  disposed  of  when 
food  enters  the  intestine?  Color  of  bile?  Why  sometimes  used  in 
housekeeping?  Use  of  bile  in  digestion  ? 


THE   SMALL   INTESTINE.  II 7 

10.  The  Pancreas  lies  along  the  lower  side  of  the  stom- 
ach.    Its  duct  opens  into  the  small  intestine  at  the  same 
place  as  the  bile-duct.     The  secretion  of  the  pancreas  is 
named  pancreatic  juice.     It  is  much  like  saliva  in  appear- 
ance, being  transparent  and  colorless.     The  pancreatic 
juice  is  one  of -the  most  important  digestive  liquids.     It 
acts  upon  starch  as  saliva  does,  turning  it  into  sugar;  it 
dissolves  albuminous  matters,  thus  completing  the  action 
of  the  gastric  juice;  and,  more  powerfully  than  bile,  it 
promotes  the  absorption  of  fatty  food. 

11.  Digestion  in  the  Small  Intestine. — The  soft  half- 
digested  food-mass  which  enters  the  intestine  from  the 
stomach,  is  named  chyme.     It  is  at  once  mixed  with  bile 
and  pancreatic  juice,  and  then,  as  it  slowly  passes  along, 
has  the  secretion  of  the  innumerable  little  glands  of  the 
mucous  membrane  of  the  small  intestine  added  to  it. 

The  result  of  the  combined  action  of  these  liquids  is 
that  any  starch  which  escaped  digestion  in  the  mouth,  is 
turned  into  sugar;  any  albuminous  substances  which 
had  not  been  fully  dissolved  in  the  stomach  are  finally 
digested;  fats,  which  are  not  acted  upon  at  all  by  either 
saliva  or  gastric  juice,  are  prepared  for  absorption. 
Digestion  in  the  small  intestine  is  on  the  whole  more 
important  than  that  which  takes  place  in  the  mouth  or 
stomach.  The  product  of  intestinal  digestion  is  a  highly 
nutritious  creamy  liquid  containing  all  the  nourishing 
matters  of  the  food.  This  liquid  is  named  chyle.  It  is 

10.  Position  of  the  pancreas  ?     Opening  of  its  duct  ?     Name  of  its 
secretion  ?     Appearance  ?    Value  ?    Action  on  various  foodstuffs  ? 

11.  What  is  chyme  ?    What  is  at  once  mixed  with  it  in  the  intes- 
tine ?     What  afterwards  ?     How  do  these  liquids  act  on  starch  ?    On 
albumens  ?    On  fats?     Where  does  the  most  important  part  of  diges- 
tion occur  ?     What  is  said  of  the  liquid  produced  by  digestion  in  the 
small  intestine  ?     Its  name  ?     For  what  is  it  ready  ? 


118  ABSORPTION 

ready  to  be  taken  up  into  the  blood  and  carried  to  every 
organ. 

12.  Absorption  from  the  Small  Intestine. — As  the  chyle 
passes  along,  it  is  gradually  absorbed  by  the  mucous 
membrane,  which  is  specially  adapted  to  fulfil  this  duty. 
Instead  of  being  nearly  smooth  like  the  mucous  mem- 
brane lining  the  mouth,  it  is  raised  up  into  numerous 
folds  (Fig.  33)  which  greatly  increase  the  extent  of  its 
surface;  and  thus  it  is  enabled  to  absorb  more  and 
quicker  than  if  it  was  stretched  smooth  and  flat.  The 


FIG.  33.— A  portion  of  the  small  intestine  opened  to  show  the  folds  of  its  mucous 
membrane. 

pockets  or  hollows  between  the  folds  also  have  their 
use.  The  chyle  collects  in  them  and  is  thus  prevented 
from  passing  along  faster  than  it  can  be  absorbed. 

13.  The  Villi  of  the  Small  Intestine. — All  over  the  mucous 
membrane  of  the  small  intestine,  both  on  its  folds  and 
between  them,  are  tiny  elevations,  which  stand  up  like 
the  pile  on  velvet.  Each  elevation  is  a  villus,  and,  small 
though  it  is,  contains  two  sets  of  tubes  or  vessels.  One 

12.  For   what   is    the   mucous   membrane   of   the   small   intestine 
specially  adapted?     How  is  the  extent  of  the  surface  of  its  mucous 
membrane  increased?     Use  of  these  folds  ?     Of  the  hollows  between 
them? 

13.  Describe  the  surface  of  the  mucous  membrane  of  the  small  in- 
testine.    What  is  a  villus  ?     What  does  each  villus  contain  ?     Use  of 
the  villi  ?     Where  does  the  chyle  absorbed  by  them  go  ? 


PLATE   III.-A  GENERAL  VIEW  OF  THE  LYMPHATICS  OR  ABSORBENTS. 
THAT  PORTION  OF  THEM  KNOWN  AS  THE  LACTEALS  IS  SEEN  AT  d,  PASSING 
FROM  THE  SMALL  INTESTINE  e  TO  THE  THORACIC  DUCT  /. 


EXPLANATION   OF    PLATE  III. 

A  GENERAL  VIEW  OP  THE  LYMPHATIC  OR  ABSORBENT  SYSTEM 
OP  VESSELS. 

e,  A  portion  of  the  small  intestine  from  which  lacteals  or  chyle- 
conveying  vessels,  d,  proceed  their  origin  within  the  villi  may  be 
seen  magnified  in  fig.  34;  f,  the  duct  called  thoracic,  into  which  the 
lacteals  open.  This  duct  passes  up  the  back  of  the  chest,  and  opens 
into  the  great  veins  at  g,  on  the  left  side  of  the  neck:  here  the  chyle 
mingles  with  the  venous  blood.  In  the  right  upper  and  lower  limbs 
the  superficial  lymphatic  vessels,  1 1 II,  which  lie  beneath  the  skin, 
are  represented.  In  the  left  upper  and  lower  limbs  the  deep  lym- 
phatic vessels  which  accompany  the  deep  blood-vessels  are  shown. 
The  lymphatic  vessels  of  the  lower  limbs  join  the  thoracic  duct  at  the 
spot  where  the  lacteals  open  into  it:  those  from  the  left  upper  limb 
and  from  the  left  side  of  the  head  and  neck  open  into  that  duct  at 
the  root  of  the  neck.  The  lymphatics  from  the  right  upper  limb  and 
from  the  right  side  of  the  head  and  neck  join  the  great  veins  at  n. 
m  m,  enlargements  called  lymphatic  glands,  situated  in  the  course  of 
the  lymphatic  vessels.  These  vessels  convey  a  fluid  called  lymph, 
which  mingles  with  the  blood  in  the  great  veins. 


THE   LACTEALS. 


set  (d,  Fig.  34)  carry  blood;  the  other,  b,  a  watery  liquid 
named  lymph.     The  villi  act  like  little  roots  or  .suckers, 
and  the  chyle  which  they  absorb, 
goes,  some  of  it  into   the  blood 
at  once,  and  some  into  the  lymph- 
vessels. 

14.  The  Lacteals. — Lymph-ves- 
sels, like  blood-vessels,  are  found 
in  nearly  every  part  of  the  body. 
Another  name  by  which  they  are 
known    is    the    absorbents.     Most 
lymph-vessels  contain  only  a  thin 
colorless  liquid,  the  lymph.      But 
when   chyle    is   being    absorbed, 
the  lymph-vessels  of   the    small 
intestine  take  up  so  much  of  it 
that  their  contents  become  white 
and  milky-looking. 

have  been  named  the  lacteals, 
from  a  Latin  word  (lac]  meaning  milk.  The  lacteals 
finally  pour  the  chyle  which  they  have  taken  up,  into  a 
tube,  named  the  thoracic  duct,  which  runs  up  to  the  bot- 
tom of  the  neck  and  there  opens  into  a  large  blood- 
vessel. 

15.  The  Large  Intestine  (CC,  AC,  TC,  DC,  SF,  R,  Fig. 
32)  is  two  or  three  times  as  wide  as  the  small,  but  only 
about  five  feet  long.     In  it  the  absorption  of  the  nourish- 
ing part  of  the  food  is  completed,  and  towards  its  lower 

14.  Where   are  lymph-vessels  found  ?    Another  name   for  them  ? 
What  do  most  contain?     What  do  those  of  the  intestine  become  filled 
with  during  digestion  ?     What  name  has  been  given  them  ?     What  do 
they  do  with  the  chyle  ?     Where  does  the  thoracic  duct  pour  its  con- 
tents into  the  blood  ? 

15.  Size  of  the  large  intestine  ?     Uses  ? 


FIG.  34.— Two  yilli  from  the 
inside  of  the  small  intestine,  mag- 
T4^r»/-^  tVi^r  nified  eighty  times;  </,  d,  blood- 
racucc  uicy  vessels;  b  and  c,  lymphatic  vessels 
or  lacteals. 


120  SUMMARY  CONCERNING  DIGESTION. 

end  the  indigestible  residue  collects,  ready  to  be  expelled 
from  the  body. 

16.  Summary. — When  digestion  and  absorption  are 
completed,  all  the  useful  portions  of  a  meal  have  at  last 
been  mixed  with  the  blood.  Some  of  them,  as  water, 
were  ready  for  absorption  without  undergoing  any 
change;  all  we  had  to  do  was  to  swallow  them,  and  the 
coats  of  the  stomach  took  them  up  at  once,  if  there  was 
not  too  much  of  them.  Others,  as  a  pinch  of  salt  or  a 
lump  of  sugar,  were  ready  to  dissolve  at  once.  Still 
others,  like  the  lean  of  meat,  and  starchy  foods,  had  to 
be  changed  by  the  digestive  liquids  before  they  could 
be  dissolved. 

Some  were  changed  by  saliva,  some  by  the  gastric 
juice,  others  by  the  liquids  of  the  intestines;  but  sooner 
or  later,  in  mouth  or  stomach  or  bowels,  they  were  made 
ready  for  absorption. 

Some  of  the  nutritive  liquid  was  absorbed  by  the 
blood-vessels  of  the  stomach;  more  by  the  blood-vessels 
of  the  intestinal  villi;  still  more  by  the  lacteals.  What 
little  may  still  have  been  left,  was  sucked  up  into  the 
blood-  and  lymph- vessels  of  the  large  intestine.  But  no 
matter  where  it  was  absorbed,  or  by  what  vessels,  it 
finally  reaches  the  blood,  and  supplies  it  with  water  and 
minerals  and  albumens  and  fats  and  sugar,  to  be  carried 
to  every  organ. 

16.  What  has  happened  when  the  digestion  and  absorption  of  a 
meal  are  completed?  Name  a  food-stuff  absorbed  without  change. 
One  which  has  to  be  simply  dissolved.  Some  which  had  to  be  changed 
by  the  digestive  juices  before  they  could  be  absorbed.  Name  the 
liquids  used  in  changing  them.  Name  the  vessels  concerned  in  the 
absorption.  With  what  does  the  absorbed  liquid  supply  the  blood  ? 


PRACTICAL   HINTS  FOR    TEACHERS.  121 


APPENDIX  TO  CHAPTER  XL 

The  main  points  in  the  anatomy  of  the  alimentary  canal  may  be 
easily  studied  on  a  kitten,  puppy,  or  rat.  Superfluous  kittens  and 
puppies  have  so  often  to  be  drowned,  that  no  unnecessary  taking  of 
life  is  called  for.  The  animal  may  be  more  mercifully  killed  by  shut- 
ting it  up  in  a  small  tight  box,  for  ten  minutes,  along  with  a  small 
sponge  soaked  in  chloroform.  A  tin  cracker-box  does  very  well. 

Cut  away,  with  strong  scissors,  the  front  of  the  chest  and  abdomen  of 
the  dead  animal,  taking  care  not  to  injure  the  contents  of  those  cavi- 
ties. Dissect  off  the  skin  on  the  front  and  sides  of  the  neck.  Re- 
move the  larynx,  trachea,  lungs,  and  heart. 

The  gullet,  a  slender  muscular  tube,  will  now  be  exposed  in  the 
neck;  trace  it  through  the  chest;  note  the  relative  positions  of  the 
abdominal  viscera  as  now  exposed,  before  displacing  any  of  them; 
then  turning  the  liver  up  out  of  the  way,  follow  the  gullet  in  the  ab- 
domen until  it  ends  in  the  stomach. 

Note  the  form  of  the  latter  organ;  its  projection  (fundus)  to  the 
left  of  the  entry  of  the  gullet;  its  great  and  small  curvatures;  its  nar- 
rower pyloric portion  on  the  right,  from  which  the  small  intestine  pro- 
ceeds. Attached  to  the  stomach,  and  hanging  down  over  the  other 
abdominal  viscera,  notice  a  thin  membrane,  the  amentum. 

Follow  and  unravel  the  coils  of  the  small  intestine,  spreading  out  as 
far  as  possible  the  delicate  membrane  (mesentery)  which  slings  it.  In 
the  mesentery  are  numerous  bands  of  fat,  running  in  which  will  be 
seen  blood-vessels  and  lacteals. 

The  termination  of  the  small  intestine  by  opening  into  the  large. 
Observe  the  ccecum  or  blind  end  of  the  latter,  projecting  on  one  side 
of  the  point  of  entry  of  the  small  intestine;  on  the  other  side  follow 
the  large  intestine  until  it  ends  at  the  anal  aperture,  cutting  away 
the  front  of  the  pelvis  to  follow  its  terminal  portion  (rectum).  The 
portion  between  the  cacum  and  the  rectum  is  the  colon. 

Spread  out  the  portion  of  the  mesentery  lying  in  the  concavity  of 
the  first  coil  (duodenum)  of  the  small  intestine;  in  it  will  be  seen  a 
glandular  mass,  the  pancreas. 

Observe  the  portal  vein  entering  the  under  side  of  the  liver  by  sev- 
eral branches.  Alongside  it  will  be  seen  the  gall-duct,  formed  by 
the  union  of  two  main  branches,  and  proceeding,  as  a  slender  tube,  to 
open  into  the  duodenum  a  short  way  from  the  pyloric  orifice  of  the 
stomach.  In  a  kitten  or  puppy  the  gall-bladder  will  be  seen  on  the 
under  side  of  the  right  half  of  the  liver. 

Note  the  spleen:  an  elongated  red  body  lying  in  the  mesentery, 
behind  and  to  the  left  of  the  stomach. 

Divide  the  gullet  at  the  top  of  the  neck,  and  the  rectum  close  to  the 
anus,  and,  severing  mesenteric  bands,  etc.,  by  which  intermediate 
portions  of  the  alimentary  canal  are  fixed,  remove  the  whole  tube; 
then  cutting  away  the  mesentery,  spread  it  out  at  full  length,  and 


122  PRACTICAL   HINTS  FOR    TEACHERS. 


note  the  relative  length  and  diameter  of  its  various  parts;  and  that 
the  small  intestine  forms  by  far  its  longest  portion. 

Open  the  stomach;  note,  in  the  rat,  that  the  mucous  membrane  lining 
the  fundus  is  thin  and  smooth,  and  is«  sharply  marked  off  from  the 
thick  corrugated  mucous  membrane  lining  the  rest  of  the  organ.  This 
is  not  the  case  in  the  stomach  of  dog,  cat,  or  man.  Pass  probes 
through  the  cardiac  orifice  into  the  gullet  and  through  the  pyloric  ori- 
fice into  the  duodenum. 


CHAPTER   XII. 
HYGIENE  OF  THE   DIGESTIVE  ORGANS. 

1.  Why  Care  of  our  Digestion  is  an  Important  Duty. — 

When  the  digestive  organs  are  all  in  good  working 
condition,  appetite  is  healthy,  our  meals  are  enjoyed,  the 
temper  is  cheerful,  the  body  vigorous  and  well  nour- 
ished, and  life  pleasant.  If  the  stomach,  liver,  or  intes- 
tines fail  in  their  duty,  the  picture  is  reversed.  Appetite 
is  wanting,  the  brain  and  muscles  are  ill  nourished,  every- 
thing is  regarded  from  a  gloomy  point  of  view,  work  of 
any  kind  is  a  burden,  and  life  a  weariness.  It  is  plain 
from  this,  that  in  most  cases,  the  man  with  a  good  di- 
gestion and,  in  consequence,  a  well-nourished  body  and 
cheerful  active  mind,  has  much  better  chances  for  suc- 
cess in  life  than  one  whose  energies  are  weighed  down 
by  bad  digestion,  and  consequent  ill  heath. 

Not  merely  from  its  bearing  on  our  own  personal 
happiness  and  welfare,  but  as  a  matter  of  duty  towards 
others,  it  is  of  primary  importance  to  preserve  the 
digestive  organs  in  a  healthy  natural  state.  A  man 
with  good  digestion  is  pretty  sure  to  be  an  agreeable 
and  encouraging  friend  or  companion;  while  the  chances 
are  that  one  who  digests  badly,  will  be  irritable,  de- 
pressed, and  disagreeable. 

i.  How  does  a  good  digestion  influence  our  health  and  happiness? 
A  bad?  Our  chances  for  success  in  life?  Why  is  it  a  duty  towards 
others  to  try  and  maintain  our  digestive  organs  in  good  condition  ? 


124  DYSPEPSIA. 

2.  Dyspepsia  is  the  name  commonly  used  to  indicate 
difficult  or  painful  digestion.     It  may  take  many  forms 
and  be  due  to  imperfect  action  of  different  organs.     In 
certain  cases,  it  is,  no  doubt,  unavoidable;  some  unfortu- 
nate people  have  weak  stomachs,  or  sluggish  livers,  as 
others  have  feeble   muscles  or  poor  eyes,  from   causes 
beyond  their  control.    But  in  the  great  majority  of  cases, 
dyspepsia  is  due  to  some  imprudence  in  conduct.     Its 
most  frequent  cause  is  unwise  eating  and  drinking;  but 
mental  overwork,  neglect  of  muscular  exercise,  lack  of 
fresh  air,  late    hours,  and    improper   clothing,  all   play 
their  part  in  various  cases.     Probably  not  more  than 
one  person   out  of  five  of  those  who  live  in  towns  or 
cities,  reaches  the  age  of  forty,  without  suffering  from 
some  form  of  dyspepsia,  which  might  have  been  avoided 
by  wiser  habits  during  early  life.     Once  it  has  made  its 
appearance,  dyspepsia  is  extremely  difficult  to  get  rid 
of.     How  best  to  avoid  it,  is  therefore  a  very  important 
branch  of  hygiene. 

3.  The  Intervals  between  beginning  Meals  should  be 
not  less  than  four  hours,  five  is  better;  except  in  the  case 
of  young  children  and  invalids,  who  require  food  more 
often,  and  in  smalt  quantities  at  a  time.     As  we  have 
learned  (p.  115),  the  stomach  is  only  emptied  about  two 
and  a  half  or  three  hours  after  an  ordinary  meal.     It 
should  have  some  rest  before  being  set  again  to  work. 
During  this  rest,  it  collects  in  its  glands   material   for 
making  a  fresh  supply  of  gastric  juice.     Eating  between 

2.  What  is  dyspepsia?     Why  not  always  avoidable  ?     What  is  said 
concerning   it   in    the    majority    of   cases  ?       Most    frequent   cause  ? 
Other  causes?     What  is  said  concerning  dyspepsia  in  those  who  live 
in  cities?     Concerning  ease  of  cure? 

3.  Proper  time    between    meals  ?     Exceptions  ?      What   does    the 
stomach  collect  during  rest  ?    Why  is  eating  between  meals  injurious  ? 


PROPER    TIME   FOR   MEALS.  12$ 

meals  keeps  the  stomach  at  work  all  the  time,  and  it 
is  not  ready  to  do  its  duty  properly  when  the  meal- 
time comes. 

4.  Meals  should   be  taken  at  Regular  Hours. — Three 
meals  a  day  are  sufficient,  and  many  persons  do  better 
with  two.     Their  regularity  is  of  more  importance  than 
their  number.     The  stomach,  like  the  rest  of  our  organs, 
soon   forms   habits,  and   only  works  with  comfort  when 
they  are  not  interfered  with.     A  little  before  the  usual 
time  of  eating,  we  begin  to  feel  an  appetite,  which  grad- 
ually increases  to  a  pleasant  degree  of  hunger.    If  a  man 
keeps  at  his  work  instead  of  heeding  this  hint,  his  whole 
system  becomes  run  down  from  want  of  nourishment. 
His   stomach  itself   is  unable  to  secrete  properly,  and 
when   at  last  he  sits  down  to  eat,  utterly  tired  out,  he 
has  no  appetite,  and  his  meal  is  probably  followed  by  a 
fit  of  indigestion. 

A  heavy  meal  should  not  be  eaten  within  two  hours 
of  going  to  bed.  The  presence  of  much  food  in  the 
stomach,  is  very  apt  to  cause  troubled  sleep. 

5.  Meals  should  be  Eaten  Slowly  and  with    Pleasant 
Surroundings. — The  dinner-table  should  be  the  scene  of 
a  cheerful  gathering,  and  merry  talk.     To  bolt  a  meal 
in   gloomy  silence,  thinking  of   one's  work  or  worries, 
is  not  only  bad  manners,  but  bad  hygiene.     Talking  of 
unpleasant  things  is  often  necessary,  but  should  always 
be  put  off  until  an  hour  or  two  after  dinner,  when  one  is 
in  much  better  condition  to  meet  annoyances. 

4.  Proper  number  of  meals  ?     Why  should  they  be  taken  at  regular 
times  ?     What  happens  if  a  man  allows  his  business  to  postpone  a 
meal  much  beyond  the  proper  time  ?     What  is  said  concerning  eating 
before  bedtime  ? 

5.  What  is  said  concerning  the  dinner-table  ?     About  eating  while 
thinking  of  work  or  worry  ?    About  talking  of  unpleasant  things  ? 


126  PROPER  AMOUNT   OF  FOOD. 

6.  Some  Rest   should  be  taken  before  Eating.— When 
the  mind  or  body  is   greatly  tired,  the  digestive  organs 
will  not  act  properly.     A  man  engaged  in  any  laborious 
business  should  therefore  take  his  dinner  after  he  has 
finished  his   day's  work,  and  had  at  least  half  an  hour's 
rest.     If  he   come   straight  from  his  office  to  the  table, 
and  return  there   directly  after  eating,  he  will,  in   the 
long-run,  injure  his  health. 

The  day's  work  of  a  child  should  finish  early,  and  be 
followed,  after  an  hour's  recreation,  by  dinner.  If  there 
is  an  afternoon  session  at  school,  the  work  should  be  of 
a  kind  calling  for  little  mental  effort;  for  example,  writ- 
ing or  drawing. 

7.  Food    should  be   Eaten    Slowly. — This   ensures   its 
proper    mastication    and    thorough    mixture    with    the 
saliva  (p.  106).     Thus  the  work  of  the  stomach  and  other 
digestive  organs  is  lightened. 

Moreover,  rapid  eating  is  very  apt  to  lead  to  over- 
eating. Too  much  food  is  swallowed  before  enough 
has  been  absorbed  to  lead  to  diminution  of  the  sensa- 
tion of  hunger. 

8.  The  Proper  Amount  of  Food  varies  with  age,  work, 
and  climate.     A  person  who  has   done  growing,  needs 
only  enough    to    make    good  his    daily  waste,  while   a 
child  should  have  something  over,  to   supply  materials 
for  growth.     In  warm  weather,  less  food  is  required  than 
in  cold,  because  less  material  has  to  be  oxidized  in  the 

6.  Why  is  it  unwise  to  eat  when  very  tired?     When  should  a  man 
whose  business  is  fatiguing  dine?     Why?     What  is  said  concerning 
the  day's  work  of  a  child?     Of  afternoon  session  at  school? 

7.  Why  should  we  eat  slowly  ?     How  is  it  that  rapid  eating  may 
lead  to  over-eating  ? 

8.  Conditions  affecting  proper  amount  of  food  ?     Need  of  an  adult  ? 
Of  a  child  ?     Influence  of  weather?     What  is  a  safe  guide  ?     What  is 


THE  PROPER  DIET.  12  J 

body  (p.  82)  to  keep  up  the  animal  heat.  If  food  be 
eaten  slowly,  the  natural  appetite  is,  in  health,  a  safe 
guide.  Those  who  injure  themselves  by  over-eating,  are 
not  the  workers  who  come  to  their  meals  hungry,  but  the 
indolent  who,  having  little  appetite,  stimulate  their  pal- 
ates by  highly  flavored  food,  to  enable  them  to  eat  what 
they  have  not  earned,  and  their  bodies  do  not  want. 

An  over-distended  stomach  is  not  merely  injured  it- 
self, but  interferes  with  the  heart  and  lungs.  It  pushes 
the  diaphragm  up  against  them  and  impedes  their  move- 
ments. Hence  result  feelings  of  oppression  in  the  chest, 
shortness  of  breath,  and  faintness.  Palpitation  of  the 
heart  may  also  be  produced  :  it  is  frequent  in  that  kind 
of  dyspepsia  which  is  accompanied  by  accumulation  of 
gas  in  the  stomach. 

9.  A  Proper  Diet  contains  both  Animal  and  Vegetable 
Foods. — The  teeth  of  a  purely  flesh-eating  animal,  as  a 
tiger,  are  constructed  only  for  tearing  and  cutting. 
Those  of  a  vegetable-eater,  as  a  cow,  are  very  broad 
and  constructed  for  grinding,  except  a  few  in  front  for 
cropping  grass.  Man's  teeth  are  half-way  between  the 
purely  flesh-eating  and  purely  vegetable-eating  kind. 
Their  structure  shows  that  our  proper  food  is  both 
animal  and  vegetable. 

This  is  also  proved  by  the  fact  that  some  of  the 
digestive  liquids  found  in  the  human  alimentary  canal 
are,  like  the  saliva  (p.  106),  especially  fitted  to  digest 


said  concerning  those  who  injure  themselves  by  over-eating?  Conse- 
quences of  an  over-distended  stomach?  What  is  said  concerning 
palpitation  of  the  heart  ? 

9.  Teeth  of  a  purely  flesh-eating  animal  ?  Of  a  vegetable-eater  ?  Of 
man  ?  What  does  their  structure  show  ?  How  is  this  also  proved  ? 
When  should  less  animal  food  be  taken  ? 


128         INFLUENCE   OF  WATER   ON  DIGESTION. 

Starch,  which  is  the  chief  food  -  stuff  in  vegetables ; 
while  others,  as  gastric  juice  (p.  113),  are  adapted  to 
digest  albumen,  which  is  scarce  in  vegetables  but  abun- 
dant in  most  animal  foods. 

In  warm  weather,  when  the  body  easily  keeps  up  its 
animal  heat,  it  is  not  well  to  eat  much  animal  food. 

10.  Drinking  much  Water  during  a  Meal  is  Injurious. 
— The  gastric  juice  acts  well  only  in  warmth,  and  a 
glass  of  cold  water  cools  the  stomach  very  much, 
and  for  a  considerable  time.  Cold,  also,  drives  the 
blood  out  of  the  mucous  membrane,  just  as  it  would 
out  of  the  skin.  This  stops  or  diminishes  the  action 
of  the  glands,  which  can  only  pour  out  abundant  gastric 
juice  when  they  are  richly  supplied  with  blood.  If 
water  be  taken  slowly,  and  only  a  few  mouthfuls  at  a 
time,  a  much  smaller  quantity  will  satisfy  the  thirst, 
than  if  a  glassful  be  taken  at  a  draught.  Also,  the 
stomach  is  not  enough  cooled,  at  any  moment,  to  inter- 
fere with  digestion.  Moreover  there  is  a  limit  to  the 
amount  of  water  which  the  coats  of  the  stomach  will 
quickly  absorb.  Any  more  than  that  will  be  left  over 
and  make  the  gastric  juice  too  weak  to  work  well. 

About  a  single  glass  with  a  meal  in  cool  weather,  and 
two  glasses  in  warm,  is  a  proper  quantity. 

In  warm  weather  or  after  heating  exercise  it  is  well  to 
assuage  thirst  at  least  half  an  hour  before  going  to  table, 
so  that  the  water  may  be  absorbed  before  the  stomach 
is  called  upon  to  digest. 

10.  What  is  necessary  in  order  that  the  gastric  juice  may  act 
well  ?  What  is  the  effect  of  drinking  a  glass  of  ice-water?  How  does 
cold  act  on  the  blood  in  the  mucous  membrane  ?  What  is  the  con- 
sequence as  regards  the  glands  of  the  stomach  ?  Why  should  water 
be  drunk  slowly  ?  The  proper  quantity  with  a  meal  ?  Why  assuage 
thirst  some  time  before  eating? 


ACTION  OF  COLD   ON   THE  DIGESTIVE   ORGANS.    12Q 

11.  Exposure  of  the  Skin  to  Cold  often  causes  Disease  of 
the  Digestive  Organs. — Every  one  knows  that  eating 
certain  tilings,  as  unripe  fruit,  is  apt  to  cause  colic  and 
diarrhoea.  But  a  more  frequent  cause  of  these  com- 
plaints is  insufficient  clothing.  A  man  goes  out  on  a 
summer  morning  with  no  cotton  or  woollen  under-gar- 
ments,  gets  very  hot  at  his  day's  work,  comes  home 
tired,  and  not  able  to  withstand  any  extra  strain  on  his 
organs.  By  way  of  becoming  cooled  and  refreshed,  he 
sits,  with  no  extra  clothing,  in  a  draught.  This  chills  the 
skin  unduly,  and  the  blood  driven  from  it  (p.  78)  col- 
lects in  internal  organs  in  excessive  quantity.  A  com- 
mon result  is  that  the  person  feels  chilly  and  uncom- 
fortable before  going  to  bed,  and  is  awakened  in  the 
night  suffering  from  colic  and  diarrhoea.  Diarrhoea  is 
nearly  always  due  to  excessive  secretion  by  the  mucous 
membrane  lining  the  bowels.  This  being  inflamed 
secretes  excess  of  waterly  liquid,  like  the  membrane  lining 
the  nose  in  a  "cold  in  the  head."  In  both  cases  watery 
matter  that  ought  to  have  been  carried  off  by  the  skin  is 
driven  back  to  the  interior.  Draughts  should  always  be 
avoided,  but  especially  if  the  underclothing  be  damp 
with  perspiration.  Its  rapid  evaporation,  by  cooling  the 
skin  (p.  67)  very  fast,  much  increases  the  danger.  If, 
in  such  circumstances,  you  have  to  sit  in  a  current  of 
air,  throw  an  extra  wrap  around  you,  at  least  until  the 
clothes  next  the  skin  have  become  dry.  You  will  thus 
gain  your  end  of  getting  to  feel  cool,  nearly  as  soon  as 

ii.  What  is  apt  to  result  from  eating  unripe  fruit?  What  is  a 
more  common  cause  of  colic  ?  Example  ?  To  what  is  diarrhoea 
directly  due  ?  When  should  draughts  be  especially  avoided  ?  Why  ? 
What  should  be  done  if  you  cannot  avoid  sitting  in  a  draught  when 
perspiring  ? 


I3O  ACTION  OF  ALCOHOL  ON  THE  DIGESTIVE  ORGANS. 

if   you    neglect    this    precaution,    and    with    much    less 
danger. 

12.  The  Large  Intestine    should   be  trained  to  empty 
itself  once   a  day,  at  a   regular  hour.     Neglect   of    this 
leads   to    the    retention   of    injurious    substances  in   the 
body. 

13.  The  Action  of  Alcoholic  Drinks  on  the  Digestive 
Organs  is  such  as  to  frequently  cause  disease.     In  some 
cases  this  is  due  to  a  general  slow  poisoning  of  all  parts 
of  the  body,  enfeebling  it  and  rendering  impossible  the 
healthy  activity  of  any  organ.     Two  digestive    organs 
are,  however,  especially  apt  to  be  attacked  by  alcoholic 
disease.     They  are  the  stomach  and  the  liver. 

14.  The  Action  of  Alcohol  on  the   Stomach  is  first   to 
cause  its  mucous  membrane  to  become  overgorged  with 
blood,  or,  in  medical  language,  congested.     If  the  dose  be 
not  very  large   or  soon  repeated,  this  passes  off,  as  the 
alcohol   is  absorbed   and   carried   off  by  the   blood    to 
work  mischief  elsewhere. 

But  repeated  tippling  keeps  the  stomach  in  this 
congested  state.  Instead  of  being  allowed  a  period  of 
rest  before  every  meal,  it  is  kept  excited  all  the  time 
and  very  soon  becomes  inflamed.  Appetite  is  lost  or 
replaced  by  nausea;  the  stomach,  accustomed  to  the 
powerful  alcoholic  stimulant,  does  not  pour  out  gastric 
juice  when  less  stimulating  food  enters  it,  and  dyspepsia 
is  the  consequence. 


12.  What  is  said  concerning  the  large  intestine? 

13.  Action  of  alcoholic  drinks  on  the  digestive  organs  ?     To  what 
sometimes   due  ?     What   digestive   organs  are   especially   apt   to   be 
injured  by  alcohol  ? 

14.  First   action    of  alcohol   on  the  stomach  ?     What  follows  if  a 
fresh    dose    be    not    soon    taken  ?      Effect   of    repeated     tippling  ? 


ACTION  OF  ALCOHOL    ON    THE   STOMACH.       \^l 

For  a  time,  a  person  in  this  condition  finds  that  another 
glass  of  spirits  or  wine  creates  appetite  and,  by  exciting 
the  stomach  to  secrete,  promotes  digestion.  So  he  falls 
daily  more  and  more  into  the  habit  of  drinking.  The 
consequence  is  that  the  stomach  at  last  ceases  to  be 
able  to  make  gastric  juice  at  all.  The  usual  glass  now 
fails  to  produce  appetite,  and  food  if  swallowed  is  not 
digested.  Unless  a  very  strong  effort  be  made  to  break 
the  habit,  and  skilful  treatment  be  long  employed  to 
get  the  stomach  back  into  a  healthy  state,  a  man  in  this 
condition  is  sure  to  die  a  drunkard. 

15.  A  Single  Large  Dose  of  Alcohol  or  of  a  drink  con- 
taining it  frequently  irritates  the  stomach  so  much  as  to 
cause  vomiting.     This  has  saved  the  lives  of  many  fool- 
ish people.     Occasionally  a   very  large  dose   paralyzes 
the  stomach  for  a  while,   so  that  it  does    not   absorb; 
this  is  sometimes  seen  when  a  man,  for  a  bet,  undertakes 
to  drink  a  bottle  of  whiskey  in  a   few  minutes.     If  his 
stomach  does  not  reject  it,  he  often  appears  unaffected 
for   half  an     hour    or     so:    then    suddenly     falls    down 
drunk,    and   often   dies    in    a  short   time.      This  occurs 
when   the  stomach,  having  begun  to   recover   from  the 
first  shock,  suddenly  commences  to  absorb  the  alcohol. 

16.  The  Action  of  Alcohol  on  the  Liver. — All  the  blood 
which    flows   through    the    mucous    membrane    of    the 
stomach  goes  straight  to  the  liver,  before  it  is  carried  to 
any  other  organ  of  the  body.     This  blood  of  course  takes 

Explain.      Consequences  ?     Why  is  a  tippler  apt  to  fall  more  into  the 
habit  ?     Consequences  ? 

15.  Usual   action    of   a   large   dose   of  alcohol    on    the    stomach? 
Occasional  result?     Example? 

16.  Where  does  blood  leaving  the  stomach  go  next?     What  might 
we  expect   as  regards  the  result   on   the  liver  of   alcohol-drinking? 


132  ACTION  OF  ALCOHOL    ON    THE   LIVER.      • 

with  it  whatever  it  has  absorbed  from  the  stomach.  It 
is,  therefore,  not  strange  that  the  liver  often  becomes 
diseased  from  a  man's  taking  alcoholic  drinks.  They 
cause  a  great  overgrowth  of  the  connective  tissue  (p.  13) 
of  the  liver,  giving  rise  to  what  is  known  as  fibrous  degen- 
eration. The  true  liver-substance  is  crushed  and  killed, 
and  what  remains  is  a  shrunken,  hard  rough  mass,  well 
known  to  physicians  as  "hob-nailed,"  or  "gin-drinker's 
liver." 

A  liver  in  this  condition  cannot,  of  course,  secrete  bile 
properly,  and  thus  digestion  is  imperfect. 

In  still  another  way,  the  nourishment  of  the  body  is 
very  seriously  affected.  Besides  making  bile,  the  liver 
has  another  duty.  This  is  to  take  up  from  the  blood 
the  sugar  (much  of  it  made  from  vegetable  starch,  p.  108) 
which  the  blood  has  absorbed  from  the  stomach  or  in- 
testines, and  turn  this  sugar  back  into  a  kind  of  animal 
starch,  which  is  more  fitted  to  nourish  the  muscles  and 
several  other  organs.  This  animal  starch  is  then  returned 
to  the  blood  to  be  carried  over  the  body.  A  diseased 
liver  cannot  perform  this  duty,  and  many  organs  are  in 
consequence  ill  nourished. 

What  is  fibrous  degeneration?  Gin-drinker's  liver?  Result  as  re- 
gards digestion  ?  Another  use  of  the  liver  besides  making  bile  ? 
What  becomes  of  the  animal  starch  made  in  the  liver?  Result  when 
liver  is  diseased  ? 


16 


PLATE  IV.-THE  CHIEF  ARTERIES  AND  VEINS  OF  THE  BODY. 


EXPLANATION  OF  PLATE  IV. 
THE  CIRCULATORY  ORGANS. 

The  arteries  (except  the  pulmonary)  and  the  left  side  of  the  hear! 
are  colored  red;  the  veins,  (except  the  pulmonary)  and  the  right  half 
of  the  heart  blue:  on  the  limbs  of  the  left  side  the  arteries  are  omitted 
and  only  the  superficial  veins  are  shown. 

1.  Aorta,  near  its  origin  from  the  left  ventricle  of  the  heart. 

2.  Lower  end  of  aorta. 

3.  Iliac  artery. 

4.  Femoral  artery. 

5.  Popliteal  artery;  the  continuation  of  the  femoral  which  passes  behind  the 

knee-joint. 

6.  7.  The  main  trunks  (anterior  and  posterior  tibial  arteries )  into  which  the 

popliteal  divides). 

8.  Subclavian  artery. 

9.  Brachial  artery. 

10.  Radial  artery. 

11.  Ulnar  artery. 

12.  Common  carotid  artery. 

13.  Facial  artery. 

14.  Temporal  artery. 

15.  Bight  side  of  Heart,  with  superior  vena  cava  joining  it  above,  and  inferior 

vena  cava  (16)  passing  up  to  it  from  below. 

17.  Innominate  vein,  formed  by  the  union  of  subclavian  and  jugular  veins. 

The  right  and  left  innominate  veins  unite  to  form  the  superior  cava. 

18.  Left  internal  jugular  vein. 

19.  Axillary  vein. 

20.  Basilic  vein. 

23.  Radial  vein. 

24.  Ulnar  vein. 

25.  Median  vein. 

26.  Iliac  vein. 

27.  Femoral  vein. 

28.  Long  saphenous  vein. 

29.  The  kidney;  attached  to  it  are  seen  the  renal  artery  and  vein. 
80.  Branches  of  the  pulmonary  arteries  and  veins  in  the  lung. 


CHAPTER  XIII. 
THE  CIRCULATION  OF  THE  BLOOD. 

1.  The  Circulation. — Blood  is  not  allowed  to  lie  at  rest 
in  any  part  of  the  body.     It  is  kept  all  the  time  moving 
round  and  round,  from  organ  to  organ,  through  a  set  of 
tubes,  the  blood-vessels.     This  regular  flow  of  the  blood 
is  named  the  circulation. 

2.  The   Use   of  the  Circulation.— If  blood   which   had 
been   enriched   by    the  absorption  of  nourishment  from 
the  alimentary  canal  should  remain  stationary,  the  mus- 
cles and  brain  would  be  starved.     If  blood  in  the  skin 
and  that  in  deeper  parts  did  not  change  places,  the  skin 
would  become  too  cold,  and  the  inside  of  the  body  too 
hot  (p.  78).     If   blood    in    the  muscles    were    not  kept 
moving  on,  and  fresh  blood  taking  its  place,  it  would 
soon    become   so  loaded   with   waste  matters  from   the 
working  muscles  that   it  would  poison  them.     It  has  to 
be   carried    off   to    organs  (the  lungs,   Chap.   XV.,   and 
kidneys,  Chap.  XVII.)  in  which  these  injurious  matters 
are  separated  from  it,  and   it  is  thus  made  again  ready 
for  use.     By  means  of  the  circulation,  then,  the  blood 
flows  through  every  organ  in  turn;  here  becoming  rich 

1.  What  is  the  circulation  of  the  blood  ? 

2.  How  might   blood   have   nourishment  in  it  and  yet  brain  and 
muscles  be  starved  ?     What  would  happen,  as  regards  the  heat  of  the 
body,  if  the  blood  were  not  kept  flowing  through  the  skin  ?     How 
might  the  blood  in  a  muscle  poison  it  ?     What  organs  separate  waste 
substances  from  the  blood  ?  What  is  accomplished  by  the  circulation  ? 


134  THE   ORGANS  OF  CIRCULATION. 

in  foods,  there  feeding  the  organs;  here  warmed,  and 
there  cooled;  here  loaded  with  wastes,  and  there  puri- 
fied. Thus  by  the  flowing  blood,  every  part  is  cared  for. 

3.  The  Organs  of  Circulation  are  the  heart,  the  arteries, 
the  capillaries,  and  the  veins.     The  heart  is  a  hollow  mus- 
cle which  squeezes  the  blood   on,  and  keeps  it  moving. 
The  arteries  carry  blood  from  the  heart  and  distribute 
it  over  the  body.     The   capillaries   are  very  fine  tubes 
with  very  thin  walls,  into  which  the  arteries  of  every  or- 
gan pour  their  blood.     The  veins  take  up  blood  from 
the  capillaries  and  carry  it  back  to  the  heart. 

4.  The  Blood,  as  every  one  knows,  is  a  red  liquid  which 
is  very  widely  distributed  over  the  body,  since  it  flows 
from    any    part   of   the   surface   when    the    skin    is   cut 
through.      There   are    very   few  portions   of   the    body 
into   which  blood  is    not   carried.     The  outer  layer  of 
the  skin  (Chap.  VI.),  the  hairs  and  nails,  the  hard  parts 
of   the   teeth,  and    most    cartilages   contain    no   blood; 
these  non-vascular  tissues  are  nourished  by  liquid  which 
soaks  through  the  walls  of  blood-vessels  in  neighboring 
parts. 

5.  Arterial  and  Venous  Blood. — Although  all  blood  is 
red,  it  is  not  all  the  same  tint  of  red.     In  nearly  all  ar- 
teries, the   blood,  just  sent  out   of  the  heart,  is  bright 
scarlet;  such  blood  is  named  arterial  blood.     In  nearly  all 
veins,  the  blood,  which  has  just  flowed  through  the  cap- 
illaries of  some  organ,   is  of  a  dark  purple-red  color; 
such  blood  is  named  venous  blood. 

3.  Name  the  organs  of  the  circulation.     What  is  the  heart  ?     What 
are  the  arteries  ?     The  capillaries?    The  veins  ? 

4.  Distribution   of  blood  in   the  body  ?      Portions   which   get   no 
blood  ?     How  are  the  non-vascular  tissues  nourished  ? 

5.  What  is  arterial  blood  ?    Venous  ? 


THE  BLOOD. 


135 


6.  The  Corpuscles  of  the  Blood. — Fresh-drawn  blood  is, 
to  the  unaided  eye,  a  uniform  red  liquid.  But  a  micro- 
scope shows  it  to  consist  of  a  colorless  liquid,  the  blood- 
plasma,  in  which  float  vast  numbers  of  tiny  solid  parti- 
cles, named  the  blood-corpuscles  (Fig.  35). 


FIG.  35.  Blood-corpuscles,  magnified.  At  A  the  corpuscles  are  shown  as  seen 
when  magnified  four  hundred  diameters.  The  red  corpuscles  have  adhered  to- 
gether by  their  flat  sides,  as  they  usually  do  soon  after  a  drop  of  blood  has  been 
drawn.  At  a  are  seen  colorless  corpuscles.  2?,  red  corpuscles,  very  greatly  mag- 
nified, seen  in  full  face.  C,  the  same  seen  edgewise.  Z>.  the  same,  adhering  by 
their  flat  faces,  f,  G,  H,  colorless  blood-corpuscles,  very  much  magnified. 

A  few  of  the  corpuscles  are  colorless  and  irregular  in 
form  (7%  G,  H,  /),  but  by  far  the  greater  number  are 
faintly  colored.  Seen  by  itself,  each  one  looks  pale  yel- 
low; but  a  number  crowded  together  appear  red. 

6.  What  does  a  microscope  show  blood  to  consist  of  ?  Color  and 
form  of  most  of  the  corpuscles?  Name?  Number?  Why  is  blood 
red  ?  How  may  it  be  made  yellow  ? 


136  THE  BLOOD-CORPUSCLES. 

Hence  they  are  called  the  red  corpuscles,  (B,  C,  D).  In 
blood,  the  corpuscles  are  so  closely  packed  that  there 
are  more  than  five  millions  in  a  single  drop.  It  is  this 
which  makes  the  blood  so  red;  if  you  dilute  a  drop  of 
blood  with  a  teaspoonful  of  water,  or  spread  it  out  very 
thin  on  a  piece  of  glass,  it  appears  yellow. 

7.  The  Shape  of  the  Red  Corpuscles  is  that  of  thin  circu- 
lar disks,  a  little  hollowed  out  on  each  of  their  larger 
surfaces.     If  you  made  a  piece  of  dough  into  a  round 
cake,  an  inch  across  and  a  quarter  of  an  inch  thick,  and 
then  pressed  it  between  thumb  and  finger  so  as  to  make 
a  slight  hollow  on  each  side,  you  would  have  a  very  good 
model  of  a  red  blood-corpuscle.     It  would,  however,  be 
thirty-two  hundred  times  broader  and  thicker  than  the 
real  corpuscle.     Put  in  another  way,  we   may  say  that 
three  thousand  two  hundred  red  corpuscles  placed  in  a 
line,  and  touching  one  another  by  their  edges,  would 
make  a  row  one  inch   in  length;    and  twelve   thousand 
eight  hundred,  piled  one  on  another,  would  make  a  col- 
umn an  inch  in  height. 

8.  The  Red  Corpuscles  of  other  Animals. — The  red  cor- 
puscles of  most  mammalia  (p.  9)  resemble  those  of  man 

in  being  circular  pale 
yellow  disks  slightly 
hollowed  on  each  side; 
those  of  camels  and 
dromedaries,  however, 

FIG.  36.— Red  corpuscles  of  the  frog.  are     Oval.        The     blood- 

corpuscles  of  dogs  are  so  like  those  of  man  in   size  that 

7.  Shape  of  the  red  corpuscles  ?     Illustrate.      What  is  said  of  their 
size? 

8.  How  do  the  red  corpuscles  of  most  mammalia  resemble  man's  ? 


BLOOD-PL  A  SMA .  137 

they  cannot  be  readily  distinguished;  but  in  most  cases 
the  size  is  sufficiently  different  to  enable  a  safe  opinion 
to  be  formed,  with  a  little  pains.  This  fact  has  often 
been  used  to  further  the  ends  of  justice,  in  determining 
whether  spots  of  blood  on  the  clothes  of  a  suspected 
murderer  were  really  due  to  the  cause  stated  by  him. 
The  red  blood-corpuscles  of  birds,  reptiles,  amphibians, 
and  fishes,  cannot  be  confounded  with  those  of  man, 
since  they  are  oval  and  contain  a  little  mass  in  the  cen- 
tre, which  pushes  out  their  sides  and  makes  them  pro- 
ject, instead  of  being  hollowed. 

9.  The  Use  of  the  Red  Corpuscles  is  to  carry  oxygen  over 
the  body.     When   blood  flows  through  the  lungs,  these 
corpuscles  take  oxygen  (Chap.  XV.);  as  it  flows  through 
other  organs  they  give  up  that  gas  to  them.     When  the 
corpuscles  are  laden  with  oxygen    their  color  is  bright 
red,    if   a    number  of  them   be  seen   closely  packed  to- 
gether; and  when  they  have  given  up  their  oxygen,  it  is 
dark  red.     The  different  quantity, of  oxygen  in  the  red 
corpuscles,  is  thus  the  reason   of  the  different  colors  of 
arterial  and  venous  blood. 

10.  The  Blood-Plasma  consists  of  water  with  a    good 
many  things  dissolved   in  it.     The  most   important  of 
these  are   (i)  albumens;  (2)   sugar;  (3)  minerals.     The 
plasma  has  also  floating  in  it  many  very  small  drops  of 


Exceptions?  How  may  they  be  distinguished  in  most  cases?  How 
has  this  been  used  to  further  the  ends  of  justice?  Describe  the  red 
corpuscles  of  birds,  etc. 

9.  Use  of   the  red  corpuscles  ?      When  do  they  receive   oxygen  ? 
When  give  it  up?     How  does  oxygen  affect  their  color?     Why   do 
arterial  and  venous  blood  differ  in  color  ? 

10.  Of   what   does  blood  plasma   consist?      The    most    important 
things  dissolved  in  it?     Floating  in  it?     What  does  the  plasma  con- 
tain in  addition  to  nourishing  substances  ? 


138  THE   CLOTTING  OF  BLOOD, 

fat.  In  addition  to  these  nourishing  substances,  the 
blood  which  flows  away  from  muscle  or  gland  or  brain 
contains  some  waste  substances,  which  it  is  carrying  off 
to  the  lungs  or  kidneys  for  removal  from  the  body. 

11.  The  Clotting  or  Coagulation  of  Blood.— When  blood 
is  first  drawn  from  the  living  body  it  is  perfectly  liquid, 
flowing  in  any  direction  as   easily  as  water.     Very  soon 
it  becomes  thick  and  sticky,  like  a  red  syrup;  and  at  the 
end  of  five  or  six  minutes  it  "  sets"  into  a  stiff  jelly,  which 
sticks  to  the  cup  or  basin  in  which  the  blood  is  contained, 
so  that  the  vessel  may  be  turned  upside  down  without 
spilling  a  drop.     This  alteration  of  the  blood  is  named 
clotting  or  coagulation.     It  is  due  to  a  change  of  some  of 
the  dissolved  albumens  of  the  blood,  into  a  solid  sub- 
stance named  fibrin. 

If  the  jelly  be  kept  for  half  an  hour  or  so,  it  shrinks 
and  squeezes  out  a  liquid  named  serum.  The  solid  part 
floats  in  the  serum  and  is  named  the  clot. 

12.  The  Use  of  Coagulation  is  to  save  us  from  the  risk  of 
bleeding  to  death  from  wounds.     So  long  as  the  blood  is 
flowing  in  healthy  living  blood-vessels,  no  fibrin  forms  in 
it,  and  it  does  not  clot.     But  as  soon  as  blood  gets  out- 
side of  the  vessels,  or  whenever  their  lining  is  injured, 
clotting   takes    place.      In   this    way,    the   ends    of    the 
small  blood-vessels  in  a  cut  finger  are  soon  clogged  up, 
if  we  can  only  stop  the  flow  for  a  little  and  give   time 
for  a  clot  to  form  in  them. 


11.  What  is  the  consistency  of  fresh  blood  ?     What  changes  occur 
in  it  during  the  first  five  or  six  minutes  after  it  is  drawn  ?    What  is 
the  solidifying  of  the  blood  called  ?     To  what  is   it  due  ?     What   is 
serum  ?     What  is  the  clot  ? 

12.  Use  of  coagulation  ?     When  does  it  not  occur  ?     When  does  it 
take  place?    Why  does  a  cut  finger  stop  bleeding  after  a  short  time  ? 


THE   HEART. 


139 


13.  The  Heart  (Fig.  37)  resembles  a  pear  in  form,  and 
is  placed  in  a  slanting  position  inside  the  chest,  with  its 
smaller  end  downwards.  It  lies  just  above  the  diaphragm 
(Fig.  2),  and  behind  the  lower  two-thirds  of  the  breast- 
bone. Its  upper  end,  or  base  (so  called  because  it  is  the 


FIG.  37. — The  heart  and  the  arteries  and  veins  opening  into  it,  seen  from  the 
front.  The  pulmonary  artery  has  been  cut  short  close  to  its  beginning,  i,  right 
ventricle;  2.  left  ventricle;  3,  root  of  the  pulmonary  artery;  4,  4',  4",  the  aorta;  5, 
part  of  the  right  auricle;  6,  part  of  the  left  auricle;  7,  7',  innominate  veins  joining 
the  upper  vena  cava;  8,  inferior  vena  cava;  9,  one  of  the  veins  from  the  liver,  join- 
ing the  inferior  vena  cava. 

larger  end,  although  the  upper),  projects  a  little  to  the 
right  of  that  bone,  and  its  lower  end,  or  apex,  a  little 
to  the  left,  where  it  may  easily  be  felt  beating  by  pressing 
with  the  finger  between  the  cartilages  (p.  18)  of  the 

13.  Shape  and  position  of  the  heart  ?  Where  does  its  base  project  ? 
Where  may  its  apex  be  felt  beating  ?  Its  size  ? 


I4O 


THE  PERICARDIUM. 


fifth  and  sixth  ribs.     A  healthy  heart  is  about  the  size 
of  the  clenched  fist  of  its  owner. 

14.  Interior  of  the  Heart. — When  the  heart  is  cut  open 

(Fig.  38)  it  is  found  to 
be  hollow.  Its  cavity  is 
not  single,  but  is  sepa- 
rated into  a  right  and  a 
left  chamber,  by  a  parti- 
tion which  runs  through 
it  from  base  to  apex. 
Each  chamber  consists  of 
an  upper  division,  Au, 
Au',  called  an  auricle ; 

FIG.  38.-Diagram  of  a  section  through  and    a    lower    division,     Vi 
the  heart.    Au,  Au',  auricles;  K,  V ,  ven-  .                                         . 
tricles;  cs,  upper  hollow  vein;  «,  lower  hoi-  V   ,  named   ^Ventricle.      On 
low  vein;  /*,  pulmonary  artery;  pd,  ps,  pul- 
monary veins;    A,   aorta.      Between  each  each    Side    there    IS  a  large 
auricle   and    the  corresponding    ventricle, 

and  at  the  mouth  of  pulmonary  artery  and  opening    between    the    au- 
aorta,  the  valves  which  control  the  direc- 

tion  of  the  blood-flow  are  seen.  rjcje     an(J     ventricle;      but 

there  is  no  direct  passage  from  the  cavities  on  the  right 
side  of  the  heart  to  those  on  the  left. 

The  divisions  of  the  heart  are,  therefore,  right  auricle, 
right  ventricle,  left  auricle,  left  ventricle. 

15.  The  Pericardium. — The  heart  is  surrounded  by  a 
loosely  fitting  case  or  bag,  named   the  pericardium.     The 
inside  of  this  bag  and  the  outside  of  the  heart  are  covered 
by  a  very  smooth  membrane.     In  the  space  between  the 
heart  and  its  case  there  is  in  health  a  small  quantity  of 


14  How  is  the  cavity  of  the  heart  divided  ?  Of  what  do  its  cham- 
bers consist  ?  What  is  said  of  communication  between  auricles  and 
ventricles  of  the  same  and  of  different  sides?  Name  the  divisions  of 
the  heart? 

15.  What  is  the  pericardium  ?  What  is  found  inside  it  and  outside 
the  heart ?  In  the  space  between?  Use? 


THE   VESSELS  OPENING  INTO    THE  HEART,    l^l 

liquid,  which  makes    the   surfaces   slippery,  and    allows 
the  heart  to  contract  or  expand  with  very  little  friction. 

16.  The  Vessels  opening  into  the  different  Divisions  of 
the  Heart  (Fig.38). — Veins  bring  back  blood  to  the  heart, 
and   open   into  the  auricles.     Arteries  carry  blood  from 
the  heart,  and  start  from  the  ventricles. 

The  veins  pouring  blood  into  the  right  auricle  are 
named  the  upper  (cs]  and  the  lower  (ci)  hollow  veins,  or  vena 
cavce.  They  got  this  name  because  after  death,  when 
most  veins  either  collapse  or  are  filled  with  blood, 
these  are  often  found  distended  and  empty. 

One  artery,  Py  springs  from  the  right  ventricle,  and 
carries  to  the  lungs  the  blood  brought  to  the  right  side 
of  the  heart  by  the  hollow  veins.  It  is  named  the  pul- 
monary artery. 

The  veins,  pd,ps>  which  open  into  the  left  auricle  are 
named  the  pulmonary  veins.  They  bring  blood  from  the 
lungs. 

One  artery,  A,  arises  from  the  left  ventricle  ;  it  is 
named  the  aorta.  As  it  proceeds  from  the  heart  it  di- 
vides, like  the  trunk  of  a  tree,  and  at  last  its  branches 
reach  every  organ  of  the  body  except  the  lungs. 

17.  The  Beat  of  the  Heart. — The  heart  relaxes  about 
seventy  times  a  minute,  and  takes  blood  from  the  veins; 
it  contracts  after  each  relaxation  and  forces  blood  into 
the  arteries.     This  regularly  alternating  expansion  and 
contraction,  is  known  as  the  beat  of  the  heart. 


16.  Function  of  veins?      Place  of  opening  into  heart?     Function 
and  place  of  opening  of  arteries  ?     What  veins  bring  blood  to  right 
auricle  ?    Why  so  named  ?     What  is  the  pulmonary  artery  ?     What 
veins  open  into  left  auricle  ?     Whence  do  they  bring  blood  ?     What 
is  the  aorta  ?     What  becomes  of  its  branches  ? 

17.  Describe  the  beat  of  the  heart  ? 


142  VALVES  OF    THE  HEART. 

18.  The  Valves  of  the  Heart  only  permit  blood  to  flow 
through  it  in  one  direction.  When  the  heart  -is  expand- 
ing and  receiving  blood,  none  flows  back  into  the  ven- 
tricles from  the  arteries,  because  the  semilunar  (half- 
moon-shaped}  valves •,  at  the  mouths  of  the  pulmonary 
artery  and  aorta,  block  the  road.  They  will  open  out- 
wards from  the  heart,  and  let  blood  flow  from  the  ventri- 
cle, but  they  will  not  open  the  other  way  and  let  blood 
flow  back  from  the  artery  into  the  heart. 

When  the  heart  dilates,  it  fills  with  blood  from  the  veins. 
Then  a  ring  of  muscle  round  the  mouth  of  each  vein  close 
to  the  heart,  contracts  and  narrows  the  opening.  Next 
the  auricles  contract,  and  the  only  way  each  can  drive 
the  blood  collected  in  it,  is  into  the  ventricle  of  the  same 
side.  Immediately  afterwards  the  ventricles  contract 
and  squeeze  on  the  blood  which  has  collected  in  them. 
This  blood  would  go  back  into  the  auricles  but  for  the 
valves  which  lie  in  the  openings  between  each  auricle 
and  its  ventricle,  and  only  open  towards  the  ventricle. 
As  soon  as  any  blood  tries  to  flow  back,  the  valves  close 
and  block  the  road,  so  the  only  way  the  contracting  ven- 
tricle can  send  its  blood  is  on  into  the  arteries. 

The  valve  between  the  right  auricle  and  ventricle  is 
named  the  tricuspid  or  three-pointed  valve.  That  between 
the  left  auricle  and  ventricle  is  the  bicuspid  or  two- 
pointed  valve.  It  is  sometimes  named  the  mitral  valve, 
from  being  shaped  like  the  two  points  of  a  bishop's  mitre. 

18.  Use  of  the  valves  of  the  heart  ?  Position  of  semilunar  valves  ? 
Action  ?  How  are  the  mouths  of  the  veins  narrowed  before  the  auri- 
cles contract  ?  Where  does  each  auricle  pump  its  blood  ?  What  hap- 
pens after  the  auricles  have  contracted  ?  Why  does  not  blood  flow 
back  in  the  auricles  when  the  ventricles  contract  ?  Where  do  the 
ventricles  pump  blood  ?  Where  is  the  tricuspid  valve  ?  The  mitral  ? 


THE    COURSE   OF   THE  BLOOD-FLOW. 


19.  The   Course   of  the  Blood-Flow. 

blood,  starting  from  any  chamber  of 
the  heart  returns  there  after  a  short 
time,  and  starts  from  it  again.  This  is 
why  the  blood-flow  is  called  a  circula- 
tion. The  return  is  not  direct;  blood 
leaving  the  left  side  of  the  heart  comes 
back  first  to  the  right,  and  blood  start- 
ing from  the  right  side  returns  first  to 
the  left. 

How  this  occurs  may  be  easily  un- 
derstood by  examining  Fig.  39,  which 
represents,  in  a  general  way,  the  heart 
and  blood-vessels.  Starting  from  the 
left  ventricle,/",  blood  flows  along  the 
aorta,  m,  and  its  branches,  to  all  parts 
except  the  lungs.*  These  branches 
end  in  the  very  small  and  very 
numerous  capillaries,  /,  of  the  mus- 
cles, and  skin,  and  mucous  membranes, 
and  so  forth.  From  these  capillaries 
the  blood  is  collected  by  veins,  which 
unite  to  make  the  hollow  veins,  k> 
which  pour  it  into  the  right  auricle. 
From  right  auricle  it 'is  sent  to  right 


Any  portion  of 


FIG.  39.— Diagram  of 
the  circulatory  organs, 
to  show  the  course  of 
the  blood-flow,  d,  right 
auricle  of  the  heart;  g; 
right  ventricle;  £,  pul- 
monary artery  and  its 
branches;  a,  the  capil- 
laries of  the  lungs;  c, 
the  pulmonary  veins;  t, 
the  left  auricle  of  the 
heart;  f,  the  left  ventri- 
cle; m,  the  aorta,  di- 
viding into  the  smaller 
arteries;  /,  the  capilla- 
ries of  all  the  organs 
except  the  lungs;  A,  the 
veins  bringing  to  the 
right  auricle  blood  from 
all  parts  of  the  body 
but  the  lungs;  A,  the 
pericardium. 


ventricle,  and   thence  by   the  pulmonary  artery  and  its 

19.  Why  is  the  blood  flow  called  a  circulation  ?  To  which  side  of  the 
heart  does  blood  which  has  last  left  the  right  ventricle  first  return  ? 
Starting  from  the  left  ventricle,  describe  the  course  taken  by  the 
blood  until  it  gets  back  there.  How  often  does  the  blood  come  back; 
to  the  heart  in  making  a  complete  circulation  ? 


*  Some  branches  of  the  aorta  carry  a  little  blood  to  the  lungs;  but  for  the  pur. 
pose  of  getting  a  general  idea  of  the  blood-flow  this  may  be  neglected, 


144    SYSTEMIC  AND  PULMONARY  CIRCULATIONS. 

branches,  b,  to  the  lungs.  There  it  flows  through  the 
pulmonary  capillaries,  a,  and  is  collected  from  them 
into  the  pulmonary  veins,  r,  which  convey  it  to  the  left 
auricle;  thence  it  flows  to  the  left  ventricle,  and  com- 
mences its  round  once  more. 

The  valves  of  the  heart  only  let  the  blood  flow  in 
the  direction  of  the  arrows  in  Fig.  39.  If  you  start  at 
any  point  in  that  figure  and  follow  along  in  the  direc- 
tion pointed  by  the  arrows,  you  will  find  that  the  blood 
cannot  flow  back  at  once,  to  the  side  of  the  heart  it 
started  from.  To  make  a  complete  circulation,  it  twice 
leaves,  and  twice  returns  to,  the  heart. 

20.  The  Systemic  and  Pulmonary  Circulations. — To  get 
from  the  left  side  of  the  heart  to  the  right,  the  blood 
must  flow  through  the  arteries,  capillaries,  and  veins  of 
the  body  in  general.     This  flow,  from  left  ventricle  to 
right  auricle,  is  often  named  the  systemic  circulation.     To 
get  from  the  right  side  of  the  heart  to  the  left,  blood 
must  flow  through  the  arteries,  capillaries,  and  veins  of 
the  lungs.     This  flow,  from  right  ventricle  to  left  auri- 
cle, is  often  named  the  pulmonary  circulation.     It  is  clear, 
however,  that  neither  is  a  circulation  in  the  proper  mean- 
ing of  the   word,  for  after  completing  it,  the   blood   is 
not  back  again  at  the  place  it  started    from.     In   order 
that  it  may  be,  it  must  go  through  both  these  circula- 
tions. 

21.  Illustration. — We  may  compare  the  blood- supply 
of  the  body  to  the  water-supply  of  a  city.     The  left  side 
of  the  heart  answers  to  the  reservoir,  and  the  arteries  to 

20.  What  is  the  systemic  circulation?     The  pulmonary?    Why  is 
neither  a  circulation,  strictly  speaking  ? 

21.  Compare  the  blood-supply  of  the  body  to  the  water-supply  of  a 
city.     In  what  respects  is  it  essentially  different  ?     What  would  have 


THE  PULSE.  145 

the  water-mains.  They  begin  at  the  heart,  and  are  very 
much  branched  except  close  to  it.  The  aorta  answers 
to  the  main  aqueduct  leaving  the  reservoir,  and  there 
single,  but  giving  off  branches  and  becoming  more  and 
more  divided  the  farther  we  follow  it.  At  last  the  water- 
main  ends  in  numerous  but  very  much  smaller  tubes  to 
supply  various  houses,  as  the  branches  of  the  aorta  sup- 
ply different  organs. 

The  course  of  the  blood  differs,  however,  essentially 
from  that  of  the  water-supply  of  a  city,  for  the  *sed 
water  does  not  return  to  the  reservoir,  whereas  the 
blood  is  carried  back  to  the  heart.  Instead  of  having  a 
large  supply  of  liquid  stored  up  as  in  a  reservoir,  there 
is  at  any  one  time  only  quite  a  small  amount  in  the 
heart,  but  this  is  steadily  replaced  by  the  inflow  through 
the  veins  as  fast  as  it  is  carried  off  by  outflow  through 
the  arteries. 

If  the  water  used  in  the  city  were  all  carried  back 
through  the  sewers  (answering  to  the  veins),  to  another 
reservoir  placed  beside  the  one  it  started  from;  and  thence 
were  carried  by  a  different  set  of  pipes  (the  pulmonary 
artery  and  its  branches)  into  a  purifying  apparatus;  and 
then  back  to  the  first  reservoir,  the  whole  process  would 
be  much  like  the  circulation  of  the  blood.  The  two  reser- 
voirs would  represent  the  heart,  which  is  double,  and  the 
purifying  apparatus  would  represent  the  lungs. 

22.  The  Pulse. — The  arteries  are  as  elastic  as  rubber 
tubing.  Every  time  the  heart  beats  and  forces  blood 
into  them,  their  walls  are  stretched  to  make  room  for  it. 
When  an  artery  lies  near  the  surface,  this  stretching 

to  be  done  with  the  used  water  to  make  the  illustration  complete? 
What  would  represent  the  lungs  ? 
22.  What  is  the  pulse  ? 


146 


THE   CAPILLARIES. 


can  be  felt  through  the  skin.  It  is  known  as  theflutse. 
The  number  of  pulses  in  a  minute,  therefore,  tells  the 
rate  at  which  the  heart  is  beating. 


FIG.  40.— A  small  portion  of  the  capillary  network  of  the  web  between  a  frog's 
toes,  as  seen  with  a  microscope,  a,  a  small  artery  feeding  the  capillaries;  v,  v, 
small  veins  carrying  blood  back  from  the  latter.  The  arrows  indicate  the  direc- 
tion of  the  blood-flow. 

23.  The  Capillaries  (Fig.  40)  are  such  tiny  tubes  that 
they  cannot  be  seen  without  a  microscope.  Their  vast 
number  makes  up  for  their  small  size;  in  most  organs 

23.  What  is  said  of  the  size  of  the  capillaries  ?  Of  their  number? 
Illustrate.  How  does  the  blood  do  its  work  while  flowing  through 
them  ?  Illustrate. 


ARTERIAL-  AND   VENOUS-BLOOD   VESSELS.       147 

they  are  so  closely  packed  that  a  pin's  point  cannot  be 
inserted  without  wounding  some  of  them.  This  is  illus- 
trated when  the  skin  is  pricked.  The  blood  in  it  is  not 
lying  loose  but  is  flowing  in  capillaries.  We  cannot  in- 
sert a  needle  deeper  than  the  epidermis  without  wound- 
ing some  of  these  capillaries  and  causing  bleeding. 

It  is  while  flowing  in  the  capillaries  that  the  blood 
does  its  work.  Their  walls  are  so  thin  that  nourishing 
matters  easily  soak  through  them  to  feed  the  organs; 
and  the  waste  matters  of  the  organs  readily  pass 
through  the  walls  of  these  tiny  vessels  into  the  blood. 

Imagine  a  piece  of  the  finest  net,  with  all  its  threads 
consisting  of  hollow  tubes,  and  diminished  twenty 
times  in  size,  and  you  will  have  some  idea  of  the 
fine  networks  formed  by  the  capillaries  in  the  various 
organs. 

24.  Which  Vessels  contain  Arterial  and  which  Venous 
Blood. — As  blood  flows  through  the  capillaries  of  the 
lungs,  its  red  corpuscles  take  up  oxygen  from  the  air 
(Chap.  XV.).  The  blood  thus  becomes  bright  red  or  ar- 
terial (p.  134).  It  flows,  keeping  this  color,  through  the 
left  auricle  and  ventricle  of  the  heart,  and  along  the 
aorta  and  its  branches  (the  systemic  arteries),  which  con- 
vey it  to  the  body  in  general.  These  arteries  pour  the 
blood  into  the  capillaries  of  all  organs  except  the  lungs. 
As  it  flows  through  these  systemic  capillaries  the  blood 
gives  up  its  oxygen  to  the  organs  and  becomes  dark- 
colored.  It  is  then  collected  into  the  systemic  veins, 
and,  still  of  a  dark  color,  is  conveyed  to  the  right  auri- 
cle, right  ventricle,  and  thence  by  the  pulmonary  artery 

24.  In  what  vessels  does  the  blood  become  arterial  ?  Through 
what  part  of  its  course  does  it  keep  its  bright  color  ?  Where  does 
it  lose  it?  Why?  Describe  its  course  until  it  becomes  bright 


148  APPENDIX    TO   CHAPTER  XIII. 

to  the  lungs,  when  it  once  more  receives  oxygen  and 
becomes  bright  red. 

Thus  the  pulmonary  veins  differ  from  all  other  veins 
in  containing  arterial  blood;  and  the  pulmonary  artery 
and  its  branches,  from  all  other  arteries  in  containing 
venous  blood.  The  ancient  anatomists  accordingly  named 
the  pulmonary  artery,  the  arterious  vein. 

In  Fig.  39,  the  vessels  which  convey  venous  blood  are 
shaded. 

again.  How  do  the  pulmonary  veins  differ  from  all  other  veins  ? 
The  pulmonary  artery  and  its  branches  from  all  other  arteries  ? 


APPENDIX  TO  CHAPTER  XIII. 

THE  BLOOD. 

Many  of  the  main  facts  pertaining  to  the  structure  and  composition 
of  blood  may  be  easily  demonstrated  as  follows: 

1.  Kill  a  frog  with  ether  (p.  46);  cut  off  its  head,  and  collect  on  a 
piece  of  glass  a  drop  of  the  blood  which  flows  out.     Spread  out  the 
drop  so  that  it  forms   a  thin  layer.      Hold  the  glass  up  against  the 
light,  and  examine  the  blood  with  a  hand-lens  magnifying  four  or 
five  diameters.     The  corpuscles  will  be  readily  seen  floating  in  the 
plasma. 

2.  Wind  tightly  a  piece  of  twine  around  the  last  joint  of  a  finger; 
then,  with  a  needle,   prick  the  skin  near  the  root  of   the  nail.     A 
large  drop  of  blood  will  exude.     Spread  it  out  on  a  piece  of  glass  and 
examine,  as  described  above  for  frog's  blood.    The  corpuscles  will  be 
seen  floating  in  the  blood-liquid,  but  not  so  easily  as  in  frog's  blood, 
since  those  of  man  are  considerably  smaller. 

3.  Obtaining  a  large  drop  of  human  blood  as  above  described  (2), 
note  (a)  that  as  it  flows  from  the  wound  it    is  perfectly  liquid  ;  (b) 
that  it  is  red  and  very  opaque;  (c)  spread  it  out  very  thin  on  the  glass; 
note  that  it  then  looks  yellow  when  held  over  a  sheet  of  white  paper; 
(d)  mix  a  similar  drop  with  a  teaspoonful  of  water   in    a   test  tube; 
note  that  the  mixture  is  yellowish,  or,  if  not,  becomes  so  on  further 
dilution. 

4.  Place  another  large  drop  of  human  blood,    obtained  as  above 
indicated,  on  a  clean  piece  of  glass.     To  prevent  drying,  cover  by 
inverting  over  the  drop  a  small  glass  whose  interior  has  been  moist- 
ened with  water.     In  four  or  five  minutes  remove  the  wine-glass  and 
note  that  the  blood-drop  has  set  into  a  firm  jelly.     Replace  the  moist 


APPENDIX  TO   CHAPTER  XIII.  H9 

glass,  and  in  half  an  hour  examine  again.     The  blood  will  then  have 
separated  into  a  tiny  red  clot,  lying  in  nearly  colorless  serum. 

5.  If  a  slaughter  house  is  accessible,  the  clotting  of  blood  may  be 
still  better  illustrated.     Provide  two  large  wide-necked  glass  bottles 
and  a  bundle  of  twigs.     When  the  butcher  bleeds  an  animal,  collect 
in  one  bottle  some  blood,  taking  care  that  nothing  else  (contents  of 
the  stomach,  for  example,  when  the  animal  is  bled,  as  is  often  done, 
by  cutting  i»s   throat)  gets  mixed  with  it.     Put  this  bottle  aside  until 
the  blood  clots,  and  carry  it  home  with  the  least  possible  shaking. 
Next  day  the  mass  will  exhibit  a  beautiful    clot  floating  in  serum. 
The  latter  will  probably  be  tinted  red,  as  the  jolting  in  conveying  the 
specimen  from  the  slaughter-house  shakes  some  of  the  red  corpuscles 
out  of  the  clot  into  the  serum. 

6.  In  the  other  bottle  collect  blood  and  stir  it  vigorously  with  the 
twigs  for  three  or  four  minutes.      Next  day  this   specimen  will  not 
have  clotted,   but  on  the  twigs  will  be  found  a  quantity  of  stringy 
elastic  material  (fibrin),  which  becomes  pure  white  when  thoroughly 
washed  with  water. 

7.  Take   some  of  the   serum  from  specimen  5.      Observe  that  it 
does  not  coagulate  spontaneously.      Heat  it   in  a  test-tube  over  a 
spirit-lamp;  its  albumen  will  then  coagulate,  like  the  white  of  a  hard- 
boiled  egg,  and  the  whole  will  become  solid. 

8.  Place  a  small  quantity  of  whipped  blood  (6)  on  a  piece  of  plati- 
num foil.     Heat  over  a  spirit-lamp.    After  the  drop  dries  it  blackens, 
showing  that  it  contains  much  animal  matter.     As  the  heating  is  con- 
tinued this  is  burnt  away,  and  a  white  ash,  consisting  of  the  mineral 
constituents  of  the  blood,  is  left. 

THE  CIRCULATORY  ORGANS. 

1.  In  the  following  directions  "dorsal"  means  the  side  of  the  heart 
naturally  turned  towards  the  vertebral  column,    "ventral"  the  side 
next  the  breast-bone;  "right"  and  "left"  refer  to  the  proper  right 
and  left  of  the  heart  when  in  its  natural  position  in  the  body;  "  an- 
terior" means  more  towards  the  head  in  the  natural  position  of  the 
parts;  and  "posterior"  the  part  turned  away  from  the  head. 

2.  Get  your  butcher  to  obtain  for  you  a  sheep's  heart,  not  cut  out 
of  the  bag  (pericardium),  and  still  connected  with  the  lungs.    Impress 
upon  him  that  no  hole  must  be  punctured  in  the  heart,  such  as  is  usu- 
ally made  when  a  slaughtered  sheep  is  cut  up  for  market. 

3.  Place  the  heart  and  lungs  on  their  dorsal  sides  on  a  table  in 
their  natural  relative  positions,  and  with  the  windpipe  directed  away 
from  you.     Note  the  loose  bag  (pericardium}  in  which  the  heart  lies, 
and  the  piece  of  midriff  (diaphragm)  which  usually  is  found  attached 
to  its  posterior  end. 

4.  Carefully  dissecting  away  adherent  fat,  etc.,  trace  the  vessels 
below  named  until  they  enter  the  pericardium.     Be  very  careful  not 
to  cut  the  veins,  which,  being  thin,  collapse  when  empty,  and  may 
be  easily  overlooked  until  injured.     As  each  vein  is  found  stuff  it 
with  raw  cotton,  which  makes  its  dissection  much  easier. 

a.   The  vena  cava  inferior:  find  it  on  the  under  (abdominal)  side  of 
the  diaphragm;  thence  follow  it  until  it  enters  the  pericardium,  about 


APPENDIX   TO   CHAPTER  Xlll. 

three  inches  further  up;  to  follow  it  in  this  part  of  its  course,  turn 
the  right  lung  towards  your  left  and  the  heart  towards  your  right. 

The  vein,  just  below  the  diaphragm,  may  be  seen  to  receive  several 
large  vessels,  the  hepatic  veins. 

As  it  passes  through  the  midriff,  two  veins  from  that  organ  enter  it. 

b.  Superior  vena  cava:  seek  its  lower  end,  entering  the  pericardium 
about  one  inch  above  the  entry  of  the  inferior  cava;  thence  trace  it 
up  to  the  point  where  it  has  been  cut  across;  stuff  and  clean  it. 

c.  Between  the  ends  of  the  two  venae  cavae  will  be  seen  the  two 
right  pulmonary  veins,  proceeding  from  the   lung  and  entering  the 
pericardium;  clean  and  stuff  them. 

5.  Turn  the  right  lung  and  the  heart  back  into  their  natural  posi- 
tions; clear  away  the  loose  fat  in  front  of  the  pericardium,  and  seek 
and  clean  the  following  vessels  in  the  mass  of  tissue  lying  anterior  to 
the  heart,  and  on  the  ventral  side  of  the  windpipe. 

#.  The  aorta:  immediately  on  leaving  the  pericardium  this  vessel 
gives  off  a  large  branch;  it  then  arches  back  and  runs  down  behind 
the  heart  and  lungs,  giving  off  several  branches  on  its  way. 

b.  The  pulmonary  artery:  this  will  be  found  imbedded  in  fat  on  the 
dorsal  side  of  the  aorta.     After  a  course,  outside  the  pericardium,  of 
about  an  inch,  it  ends  by  dividing  into  two  large  branches  (right  and 
left  pulmonary  arteries),  which  subdivide  into  smaller  vessels  as  they 
enter  the  lungs. 

c.  Observe  the  thickness  and  firmness  of  the  arterial  walls  as  com- 
pared with  those  of  the  veins;  they  stand  out  without  being  stuffed. 

6.  Notice,  on  the  ventral  side  of  the  left  pulmonary  artery,  the  left 
pulmonary  veins  passing  from  the  lung  into  the  pericardium. 

7.  Slit  open  the  pericardiac  bag,  and  note  its  smooth,  moist,  glis- 
tening inner  surface,  and  the  similar  character  of  the  outer  surface  of 
the  heart.     Cut  away  the  pericardium  carefully  from  the  entrances 
of  the  various  vessels  which  you  have  already  traced  to  it.     As  this 
is  done,  you  will  notice  that  inside  the  pericardium  the  pulmonary 
artery  lies  on  the  ventral  side  of  the  aorta. 

9.  Note  the  general  form  of  the  heart — that  of  a  cone  with  its  apex 
turned  towards  the  diaphragm.     Very  carefully  dissect  out  the  entry 
of  the  pulmonary  veins  into  the  heart.     It  will  probably  seem  as  if 
the  right  pulmonary  veins  and  the  inferior  cava  opened  into  the  same 
portion  of  the  organ,  but  it  will  be  found  subsequently  (13,  a)  that  such 
is  not  really  the  case.     Note  on  the  exterior  of  the  organ  the  follow- 
ing points: 

a.  Its  upper  flabby  auricular  portion  into  which  the  veins  open, 
and  its  thicker  lower  ventricular  part. 

b.  Running  around  the  top  of  the  ventricles  is  a  band  of  fat,  an 
offshoot  of  which  runs  obliquely  down  the  front  of  the  heart,  passing 
to  the  right  of  its  apex,  and  indicating  externally  the  position  of  the 
internal    partition,  or   septum,  which   separates    the    right    ventricle, 
which    does    not  reach  the  apex  of   the    heart,  from  the  left,  which 
does. 

10.  Dissect  away  very  carefully  the  collection^  of   fat  around    the 
origins  of  the  great  arterial  trunks  and  that  around  the  base  of  the 
ventricles. 


APPENDIX   TO  CHAPTER  XIII. 


11.  Open  the  right   ventricle  by    passing   the   blade  of   a   scalpel 
through  the  heart  about  an  inch  from  the  upper  border  of  the  ventri- 
cle, and  on  the  right  of  the  band  of  fat  marking  externally  the  limits 
of  the  ventricles,  and  noted  above  (9,  b\  and  then  cut  down  towards 
the  apex,  keeping  on  the  right  of  this  line;  cut  off  the  pulmonary 
artery  about  an  inch  above  its  origin  from  the  heart,  and  open  the 
right  auricle  by  cutting    a    bit    out  of    its  wall,  to   the   left   of   the 
entrances  of  the  vense  cavae.     On  raising  up  by  its  point  the  wedge- 
shaped  flap  cut  from  the  wall  of  the  ventricle,  the  cavity  of  the  latter 
will  be  exposed. 

a.  Pass  the  handle  of  a  scalpel  from  the  ventricle  into  the  auricle, 
and  also  from  the  ventricle  into  the  pulmonary  artery,  and  make  out 
thoroughly  the  relations  of  these  openings. 

b.  Slit  open  the  right  auricle.     Observe  the  apertures  of  the  vena 
cavtz,  and   note   that   the   pulmonary   veins   do   not  open  into  this 
auricle.  % 

12.  Raise  up  by  its  apex  the  flap  cut  out  of  the  ventricular  wall, 
and    if    necessary  prolong  the  cuts  more    towards  the    base  of  the 
ventricle  until  the  divisions  of  the  tricuspid  valve  come  into  view. 

a.  Note  the  muscular  cord  (not  found  in  the  human  heart)  stretch- 
ing across  this  ventricle.     Also  the  prolongation    of  the  ventricular 
cavity  towards  the  aperture  of  the  pulmonary  artery. 

b.  Cut  away  the  right  auricle,  and  examine  carefully  the  tricuspid 
valve,  composed  of  three  membranous  flexible  flaps,   thinning  away 
towards   their   free   edges:    proceeding    from    near  these  edges  are 
strong  tendinous  cords  (chorda  tendinece),  which  are  attached  at  their 
other  ends   to  muscular  elevations  (papillary  muscles}  of  the  wall  of 
the  ventricle. 

c.  Slit  up  the  right  ventricle  until  the  origin  of  the  pulmonary  ar- 
tery comes  into  view.     Looking  carefully  for  the  flaps  of  the  semilunar 
valves,  prolong  your  cut  between  two  of  them  so  as  to  open  the  bit  of 
pulmonary  artery  still  attached  to  the  heart.     Spread  out  the  artery 
and  examine  the  valves. 

d.  Each  flap  makes,  with  the  wall  of  the  artery,  a  pouch,  opposite 
which  the  arterial  wall  is  slightly  dilated.     The  free  edge  of  the  valve 
is  turned  from  the  heart,  and  has  in  its  middle  a  little  nodule  (corpus 
A  ran  tif). 

13.  Open  the  left  ventricle  in  a  manner  similar  to  that  employed 
for  the  right.     Then  open  the  left  auricle  by  cutting  a  bit  out  of  its 
wall  above  the  appendage.      Cut  the  aorta  off  about  half  an  inch 
above  its  origin  from  the  heart.     The  aperture   between  left  auricle 
and  left  ventricle  can  now  be  examined;  also   the   passage  from  the 
ventricle  into  the  aorta,  and  the  entry  of  the  pulmonary  veins  into 
the  auricle;  and  the  septum  between  the  auricles  and  that  between  the 
ventricles. 

a.  Pass  the  handle  of  a  scalpel  from  the  ventricle  into  the  auricle; 
another  from  the  ventricle  into  the  aorta;  and  pass  also  probes  into 
the  points  of  entrance  of  the  pulmonary  veins.     Observe  that  no  other 
veins  open  into  the  left  auricle. 

b.  Note  the  great  thickness  of  the  wall  of  the  left  ventricle,  as  com- 
pared with  that  of  the  right  ventricle  or  of  either  of  the  auricles. 


152  APPENDIX   TO   CHAPTER  XIII. 

f.  Carefully  raise  the  wedge-shaped  flap  of  the  left  ventricle,  and 
•cut  on  towards  the  base  of  the  heart,  until  the  valve  (mitral}  between 
auricle  and  ventricle  is  brought  into  view;  one  of  its  two  flaps  will  be 
seen  to  lie  between  the  auriculo-ventricular  opening  and  the  origin  of 
the  aorta. 

Examine  in  these  flaps  their  texture,  the  chordae  tendineas,  the 
papillary  muscles,  etc.,  as  in  the  case  of  the  right  side  of  the  heart 
(12). 

d.  Examine  the  semilunar  valves  at  the  exit  of  the  aorta;  then  cut- 
ting up  carefully  between  two  of  them,  examine  the  bit  of  aorta  still 
left  attached  to  the  heart,  and  note  the  valves  more  carefully  as  de- 
scribed in  12,  d. 

14.  Examine  a  piece  of  aorta.  Note  that  when  empty  it  does  not 
collapse;  the  thickness  of  its  wall;  its  extensibility  in  all  directions; 
its  elasticity. 

^5.  Compare  with  the  artery  the  thin-walled  flabby  veins  which 
open  into  the  heart. 


CHAPTER  XIV. 

HYGIENE  OF  THE  CIRCULATORY  ORGANS. 

1.  To  Ensure  a  Healthy  and  Regular  Circulation  of  the 
blood,   the  skin   must   be   kept  warm.     Cold,  we   have 
learned   (p.  72),    contracts  its  blood-vessels  and  drives 
the  blood  elsewhere.     This  does  no  harm  if  it  be  only 
for  a  short  time;  indeed   often  does  good.     But  a  pro- 
longed chill  of  the  surface  is  very  apt  to  cause  disease  of 
some  internal  organ,  by  keeping  it  overfilled  with  blood, 
or  congested. 

A  blush  is  a  brief  healthy  congestion  of  the  skin  of  the 
face.  It  may  be  compared  to  the  flushing  of  the  mucous 
membrane  of  the  stomach  when  gastric  juice  is  being 
secreted.  In  each  case,  the  temporary  rush  of  blood  to 
the  part  nourishes  it.  But  continued  overfulness  of 
blood  has  an  opposite  effect.  Too  much  liquid  from 
the  blood  soaks  through  the  walls  of  the  capillaries, 
and  the  organ  in  which  they  lie  becomes  puffy  and 
swollen. 

2.  Taking  Cold. — Congestion  produced  by  a  chill  of 
the  surface  oftenest  shows  itself  on  some  mucous  mem- 
brane.    If  that  lining  the  nose  be  attacked,  it  becomes 

1.  What  effect  has  the  temperature  of  the  skin  on  the  circulation  of 
the  blood  ?     What  is  apt  to  result  from  a  prolonged  chill  of  the  sur- 
face ?     What  is  a  blush  ?    To  what  compared  ?     Results  of  prolonged 
overfulness  of  blood  ? 

2.  Where  do  congestions  due  to  cold  most  often  occur?     Describe 


i  $4  TAKING  COLD. 

swollen,  and  we  have  difficulty  in  breathing  through  the 
nostrils.  It  is  also  irritated,  and  so  we  sneeze  (p.  174). 
Unless  proper  means  be  at  once  taken  to  stop  the  "  cold," 
the  congested  mucous  membrane  becomes  inflamed.  In 
that  case,  its  vessels  are  not  only  gorged  with  blood,  but 
the  whole  membrane  is  in  a  state  of  unhealthy  activity. 
So  far  as  its  glands  are  concerned,  this  is  shown  by  the 
unnaturally  abundant  watery  mucus  which  runs  from 
the  nostrils. 

When  deeper  parts  of  the  mucous  membrane  are 
attacked  by  "  a  cold,"  we  cannot  observe  the  details  so 
easily.  But  they  are  much  the  same  in  all  cases.  Thus 
when  the  mucous  membrane  of  the  tubes  which  carry  air 
into  the  lungs  (p.  170)  is  the  one  attacked,  we  suffer  from 
a  "  cold  on  the  chest,"  or  bronchitis.  In  this  case  we 
have  difficulty  in  breathing,  because  the  swollen  mem- 
brane narrows  the  air-passages;  we  feel  pain  and  irrita- 
tion in  the  chest;  and  we  cough  up  abundant  "  phlegm" 
or  unnatural  secretion. 

If  the  "  cold  "  attacks  the  mucous  membrane  of  the 
stomach,  we  suffer  from  loss  of  appetite  and  from  in- 
digestion, because  the  altered  secretion  fails  to  do  its 
proper  work.  The  production  of  diarrhoea  by  cold  at- 
tacking the  bowels  has  been  already  referred  to  (p.  129). 

3.  To  Avoid  taking  Cold,  the  essential  things  are  to 
wear  proper  clothing,  and,  when  perspiring,  to  guard 
against  sudden  cooling  (Chap.  VII.).  If  unavoidably 
exposed  to  conditions  apt  to  cause  a  cold,  the  risk  may 

the  condition  of  the  mucous  membrane  of  the  nose  during  a  "cold  in 
the  head."  That  of  the  air-passages  during  a  "  cold  on  the  chest." 
Results  of  a  cold  attacking  the  mucous  membrane  of  the  stomach  ? 
Of  the  bowels  ? 

3.  To  avoid  taking  cold  what  things  are  most  necessary?  What 
should  be  done  to  prevent  a  cold,  after  exposure  likely  to  cause  one  ? 


HOW   TO  AVOID    TAKING   COLD.  I  55 

be  much  diminished  by  prudence.  Try  to  get  your  skin 
warm  and  your  sweat-glands  active  as  soon  as  possible. 
Exercise  is  usually  the  best  way  to  do  this.  When  you 
feel  chilled,  and  have  some  distance  to  go  before  you  can 
reach  a  warm  room  or  get  extra  clothing,  it  is  wiser  to 
run  or  walk  or  row,  if  possible,  than  to  sit  still  and  be 
driven.  The  muscular  exercise  will  warm  the  skin.  If 
obliged  to  keep  on  wet  clothing,  throw  over  it  a  dry 
wrap.  This  will  prevent  the  wet  garments  from  drying 
rapidly,  and  thus  taking  heat  from  the  skin  too  fast 
(p.  67).  As  soon  as  possible  rub  the  whole  skin  briskly 
until  it  is  red  and  warm;  then  put  on  dry  woollen  cloth- 
ing. If  your  skin  does  not  quickly  warm  when  rubbed, 
take  a  warm  bath,  go  to  bed,  and  drink  two  or  three 
large  cups  of  hot  weak  tea  or  lemonade.  If  a  warm  bath 
cannot  be  had,  put  the  feet  in  hot  water. 

4.  Articles  of  Dress  should  not  Fit  so  Tightly  as  to  Check 
the  Blood-Flow. — Most  large  arteries  lie  deep,  but  many 
large  veins  are  near  the  surface,  just  under  the  skin. 
The  flow  of  blood  in  a  vein  is  easily  stopped  by  pres- 
sure, because  the  walls  of  the  veins  are  thin  and  flabby; 
and  when  the  vein  leading  from  any  organ  is  squeezed, 
the  blood-flow  from  it  is  hindered.  Thus  congestion  is 
produced.  . 

The  veins  most  often  impeded  in  their  work  by  tight 
clothing,  are  those  of  the  neck  and  leg. 

The  chief  veins  bringing  back  blood  from  the  head 
are  the  external  jugular  veins,  which  lie  under  the  skin, 

What  if  the  clothing  is  wet  and  cannot  be  at  once  changed  ?  What 
should  be  done  as  soon  as  you  can  change  it  ?  What  is  the  object  of 
the  exercise,  baths,  rubbing,  etc.? 

4.  How  may  tight  garments  produce  congestion  ?  Which  veins  are 
most  often  compressed  by  articles  of  ordinary  clothing?  What  are 
the  external  jugular  veins  ?  What  is  apt  to  follow  if  they  are  com- 


J5  TIGHT  GARTERS. 

one  on  each  side  of  the  neck.  A  tight  collar  or  scarf 
compresses  these  veins  and  tends  to  cause  congestion  of 
the  brain,  dizziness,  redness  of  the  eyes,  and  a  flushed 
face. 

The  chief  vein  which  brings  back  blood  from  the  foot 
and  the  lower  leg  is  named  the  long  saphenous  vein  (PI. 
IV.,  28).  It  begins  on  the  inner  side  of  the  ankle,  and 
runs  to  the  top  of  the  thigh.  A  tight  garter  compresses 
the  saphenous  vein,  into  which  many  other  veins  of  the 
leg  pour  their  blood,  and  thus  checks  the  circulation  in 
that  part  of  the  body.  The  results  are  deficient  blood- 
flow  in  the  feet.  Congestions  and  inflammations,  as 
chilblains,  more  easily  occur,  and  the  feet  are  more  apt 
to  become  cold.  If  the  garter  be  very  tight,  the  veins 
below  it  often  get  so  gorged  with  blood  that  their  walls 
stretch  and  form  swellings,  known  as  varicose  veins. 
Varicose  veins  sometimes  burst  and  cause  dangerous 
bleeding;  they  very  often  so  press  and  crush  the  tissues 
in  their  neighborhood  as  to  cause  inflammation  and 
sores.  The  stocking-supporters  now  so  commonly  used, 
which  attach  the  stocking  to  the  waistband,  are  far 
better  than  ordinary  garters. 

5.  Muscular  Exercise  Promotes  the  Circulation  of  the 
Blood,  not  only  because  it  quickens  the  beat  of  the 
heart,  but  because  the  contracting  muscles  drive  along 
the  blood  in  the  veins. 

In  the  veins  are  numerous  valves  (Fig.  41),  which  open 
towards  the  heart  and  from  the  capillaries.  Blood  flow- 
pressed?  What  is  the  saphenous  vein  ?  Describe  its  course.  How 
does  a  tight  garter  affect  the  flow  of  blood  in  the  leg  ?  Results  ?  How 
may  varicose  veins  be  produced  ?  Consequences  of  varicose  veins? 

5.  How  does  muscular  exercise  promote  the  blood-flow  ?  How  is 
blood  prevented  from  flowing  back  through  the  veins  towards  the 


THE    VALVES  OF    THE    VEINS,  1 57 

ing  in  the  proper  direction,  A,  from  capillaries  to  heart, 
is  not  hindered  on  its  road;  but  any  back-flow  in  the 
opposite  direction,  B,  is  at  once  *  • 

checked  by  the  closing  of  the  valve,  c          "^^-Si H 

This  you  may  easily  observe  on 
the  back  of  the  hand  of  any  one 
who  is  thin.  Select  a  vein  which  has  c 

no  branches  for  an  inch  or  more.  FIG.  41.— Diagram  to  illus- 
trate the  mode  of  action  of  the 

PreSS  On  Its  lower  end,  that  IS  the  valves  of  the  veins.  C,  the 

capillary,  H,  the  heart  end  of 

end  nearer  the  fingers,  so  as  to  close  the  vessel, 
it.  Then  push  the  blood  out  of  it  by  rubbing  it  with  your 
forefinger  in  a  direction  towards  the  wrist.  The  vein 
will  remain  empty  up  to  the  place  where  the  next  higher 
branch  joins  it.  At  that  place  there  is  a  valve,  which 
will  noJ;  allow  blood  to  flow  back  into  itjji  As  soon  as 
you  remove  the  pressure  from  its  lower  end,  however, 
the  vein  immediately  fills,  with  blood  brought  to  it  from 
the  capillaries  of  the  fingers.  We  learn  from  this  simple 
experiment  that  the  valves  of  the  veins  allow  blood  to 
flow  through  the  veins  to  the  heart,  but  not  from  it.  If 
the  first  vein  you  try  the  experiment  with,  does  not  be- 
have as  it  should,  try  another,  for  some  of  the  veins  on 
the  back  of  the  hand  have  branches  entering  their  deeper 
sides,  which  you  cannot  see,  and  from  which  they  be- 
come filled. 

When  the  muscles  contract  in  length  and  swell  in 
breadth  (p.  35)  they  press  on  the  veins  near  them. 
This  pressure  cannot  drive  blood  back  to  the  capillaries, 
on  account  of  the  valves  in  the  veins.  But  it  drives 
blood  on  from  the  veins  towards  the  heart,  and  thus  pro- 
capillaries  ?  How  may  we  observe  on  the  hand  the  action  of  the 
valves  of  the  veins  ?  How  do  the  muscles  promote  the  circulation  of 


158  CUTS  AND    WOUNDS. 

motes  the  circulation.  When  the  muscles  relax,  the  veins 
fill  again;  and  then  the  next  muscular  contraction  forces 
the  blood  inside  them  on  towards  the  heart.  In  this 
way  muscular  exercise  is  a  great  help  to  the  heart  in 
keeping  up  the  flow  of  blood. 

When  you  feel  cold,  a  brisk  walk  or  run,  or,  if  the 
weather  is  too  severe  for  outdoor  exercise,  indoor  gym- 
nastics, will  warm  you  sooner  and  better  than  sitting  over 
a  fire.  This  is  especially  the  case  with  coldness  of  the 
feet.  Toasting  them  over  a  fire  is  of  little  use.  They  be- 
come cold  again  almost  as  soon  as  you  leave  the  fire.  But 
a  brisk  walk  or  an  active  game  will  soon  increase  the  cir- 
culation, and  make  the  feet  warm  for  the  rest  of  the  day. 

6.  Cuts  and  Wounds. — If  the  wound  be  made  by  a  clean 
sharp  instruqfcnt  and  the  bleeding  is  not  great,  press  its 
edges  together  and  hold  them  in  place  by  a  moderately 
tight  bandage.  The  edges  of  a  gaping  wound  may  need 
to  be  held  together  by  sticking-plaster;  in  other  cases  it 
does  no  good.  Wounds  which  a  single  wider  strip  of 
plaster  will  not  hold  at  all,  may  be  nicely  held  together 
by  separate  narrow  strips  from  J-  to  f  of  an  inch  wide, 
according  to  the  nature  of  the  cut.  Taking  one,  warm 
and  fasten  it  on  the  farther  side  of  the  wound.  Pull  the 
loose  end  of  the  strip  towards  you  and  press  the  nearer 
lip  of  the  wound  against  the  farther  one,  then  fasten  the 
rest  of  the  strip  firmly  down  and  hold  it  till  it  sets. 
Proceed  in  like  way  with  the  other  strips.  Ointments 
and  salves  are  never  necessary  to  promote  the  healing  of 
a  simple  clean  cut,  and  very  often  do  harm. 

the  blood?  How  does  this  affect  the  heart?  Why  is  it  better  to 
warm  yourself  by  exercise  than  by  sitting  over  a  fire  ? 

6.  What  is  the  proper  treatment  for  a  "  clean"  cut?  If  its  edges 
gape?  How  should  sticking-plaster  be  put  on  large  cuts?  What  is 
said  of  ointments  and  salves  ?  What  should  be  done  if  there  is  dirt  in 


WOUNDS  OF  LARGE  BLOOD-VESSELS.  159 

If  the  cut  has  been  made  by  a  sharp  instrument  but 
has  dirt  or  grit  in  it,  hold  its  edges  apart  and  wash  by 
pouring  water  on  it.  Then  proceed  as  above.  Do  not 
sponge  or  wipe  it.  Either  cold  water  or  water  as  hot  as 
the  hand  can  bear  may  be  used.  Both  check  bleeding, 
the  hot  water  rather  better  than  the  cold.  Tepid  water 
promotes  bleeding. 

A  jagged  cut,  or  a  wound  made  by  a  blunt  instrument, 
does  not  heal  as  easily  as  one  made  by  a  sharp  knife. 
If  it  is  large,  or  is  on  a  part  of  the  body  where  it  is  very 
desirable  to  avoid  a  scar,  send  for  a  doctor.  Meanwhile, 
if  blood  oozes  out  fast,  check  the  bleeding  by  constant 
pressure  with  sponges  wrung  out  of  hot  water. 

7.  Wounds  of  Large  Arteries  or  Veins  need  prompt  treat- 
ment, lest  the  sufferer  die  from  loss  of  blood.  If  a  big 
vein  has  been  divided,  the  blood  will  flow  out  pretty 
steadily  and  of  a  dark  color.  If  a  large  artery  has  been 
cut,  the  blood  will  be  brighter  red  and  probably  come  out 
in  spurts.  Whichever  it  may  be,  the  proper  thing  is  to 
send  at  once  for  medical  aid,  and,  until  it  arrives,  to  stop 
the  bleeding.  Do  not  lose  time  by  trying  to  decide  whether 
the  flow  is  from  a  vein  or  an  artery,  and  whether  you 
should  apply  pressure  nearer  or  farther  from  the  heart. 
Many  large  arteries  and  veins  when  cut  bleed  nearly  as 
fast  from  one  end  as  the  other.  Press  at  once  on  the 
wound  as  hard  as  you  can,  with  a  handkerchief  or  any- 
thing of  the  sort  at  hand;  and,  when  you  have  thus  part- 
ly checked  the  bleeding,  try  pressure  all  around  the  cut, 

the  wound?     If  the  cut  is  jagged    or  apt  to    be  disfiguring?     Until 
the  doctor  arrives  ? 

7.  Why  should  wounds  of  large  blood-vessels  be  treated  at  once? 
How  does  the  flow  from  a  vein  usually  differ  from  the  bleeding  of  a 
wounded  artery  ?  What  had  best  be  done  in  either  case  ?  How  pro- 
ceed until  skilled  advice  is  obtained  ?  How  may  the  blood-flow  from 


l6o      HOW   TO   CHECK  DANGEROUS  BLEEDING. 

above  and  below,  and  on  each  side,  till  you  find  the 
place  where  it  "does  most  good."  In  deep  wounds  of 
the  arms  or  legs,  you  will  usually  find  that  pressure  both 
above  and  below  is  necessary.  A  surgeon  would  know 
where  to  apply  the  pressure  in  the  case  of  any  par- 
ticular wounds,  but  you  do  not:  your  business  is  to  find 
it  out  by  experiment  as  soon  as  you  can,  and  not  trouble 
yourself  with  any  general  rules,  which  will  fail  you  in 
most  particular  instances. 

If  the  wound  is  on  the  lower  part  of  a  limb  and  you 
find  that  you  cannot  entirely  check  the  loss  of  blood  by 
pressure  on  it  and  in  its  neighborhood,  keep  up  the  pres- 
sure and  get  some  one  to  bind  the  limb  very  tightly 
higher  up.  This  is  best  done  as  follows:  Tie  a  handker- 
chief loosely  round  the  upper  part  of  the  wounded  arm 
or  leg;  then  put  a  stick  under  it,  and  twist  the  stick 
round  and  round  until  the  handkerchief  is  so  tight  as  to 
close  the  arteries,  and  stop  all  flow  of  blood  to  the  lower 
parts  of  the  limb.  Such  stoppage  of  the  blood-flow  for 
half  an  hour  or  even  a  little  longer,  will  do  no  permanent 
harm,  while  free  bleeding  from  a  wound  in  a  large  artery 
or  vein  may  cause  death  in  three  or  four  minutes. 

If  a  person  who  has  lost  much  blood  begins  to  breathe 
slowly  and  irregularly,  give  him  a  strong  stimulant  as 
soon  as  you  can  get  it,  and  choose  the  stimulant  you  can 
get  quickest.  If  a  drugstore  is  close  by,  a  mixture 
of  a  teaspoonful  of  aromatic  spirits  of  ammonia  with 
table  spoonful  of  water  may  be  given.  If  brandy  or 
whiskey  can  be  obtained  sooner,  use  them.  The  irregu- 
lar breathing  is  a  sign  that  the  part  of  the  nervous  sys- 

a  wound  in  the  lower  part  of  the  arm  or  leg  be  stopped  ?  If  the  sufferer 
shows  signs  of  death  from  loss  of  blood,  what  should  be  done  ?  What 
is  the  use  of  the  stimulant  in  this  case  ? 


ACTION  OF  ALCOHOL    ON  BLOOD.  l6l 

tern  (Chap.  XVIII.)  which  makes  the  muscles  of  breathing 
do  their  work,  is  ceasing  to  act,  and  extra  stimulation 
must  be  given  it  for  a  while  until  the  bleeding  is 
stanched  and  blood  has  again  commenced  to  collect  in 
the  arteries. 

8.  The  Action  of  Alcoholic  Drinks  on  the  Circulation. — 
Alcohol  in  excess,  injures  the  blood,  the  arteries,  and  the 
heart. 

Even  in  moderate  doses,  it  diminishes  the  power  of  the 
blood  to  absorb  oxygen,  and  thus  decreases  the  oxida- 
tions within  the  body,  and  lowers  its  working  power  and 
its  temperature.  Large  quantities  of  alcohol  cause  the 
red  blood-corpuscles  to  become  shrunken  and  distorted, 
and  greatly  diminish  their  efficiency  as  carriers  of  oxygen 
to  all  the  organs. 

9.  The   Action  of  Alcohol  on  the  Plasma.— Continued 
alcoholic  indulgence  leads  to  an  alteration  in  the  blood- 
plasma,   lessening   its    tendency  to    form    fibrin  and  to 
clot.      Hence  even    the    slight  wounds   of   tipplers   are 
apt  to  result  in  dangerous  bleeding.     The  fibrin   is  so 
scanty  and  the  clogging  up  of  the  ends  of  cut  blood- 
vessels so  slow  (p.  138),  that  all  surgical  operations  on 
such  persons  are  attended  with  special  danger. 

10.  The  Action  of  Alcohol  on  the  Arteries. — Alcohol  tends 
to  make  fatty  matter  collect  in  the  walls  of  the  arteries. 
The  oil-drops  take  the  place  of  the  natural  tough  elastic 
material.    Thus  the  artery  is  weakened.    In  consequence, 

8.  Action  on  the  blood  of  even  moderate  doses  of  alcohol?     How 
does  this  affect  the  body  ?    Action  on  the  red  corpuscles  of  large  doses 
of  alcohol  ? 

9.  Action  on  the  blood  plasma?     Why  are  surgical  operations  on 
tipplers  especially  dangerous? 

10.  Action   of   alcohol  on    the   arteries  ?      What   is  an  aneurism  ? 
Usual  result  ? 


1 62         ACTION  OF  ALCOHOL   ON   THE  HEART. 

the  blood,  which  is  forcibly  sent  into  it  by  the  heart, 
may  stretch  its  walls  and  make  it  swell  out  and  become 
thin.  Such  a  swelling  on  an  artery  is  named  an  aneurism. 
An  aneurism  usually  ends  by  bursting,  and  the  person 
bleeds  to  death. 

11.  The  Action  of  most  Alcoholic  Drinks  on  the  Heart  is 
to  excite  it  and  hurry  its  beat.  Whether  pure  alcohol, 
diluted  with  water,  has  this  action,  is  not  certain.  It  is 
certain  that  most  ordinary  alcoholic  drinks,  as  wines  and 
spirits,  have  it.  When  the  beating  of  the  heart  is  quick- 
ened, each  contraction  of  its  muscles  takes  about  as  long 
as  when  it  beats  slower,  but  the  time  of  repose  between 
the  beats  is  shortened.  The  result  is  that  the  heart  is 
overworked.  It  has  not  sufficient  rest  for  its  proper 
nourishment,  and  gradually  undergoes  a  change  known 
as  fatty  degeneration.  Fatty  or  oily  matter  takes  the  place 
of  the  proper  muscle-substance,  and  the  heart,  becoming 
more  and  more  weakened,  at  last  cannot  pump  the  blood 
over  the  body.  The  consequence,  of  course,  is  death. 
Fatty  degeneration  of  the  heart  is  so  often  due  to  indul- 
gence in  alcoholic  stimulants,  that  a  fatty  heart  is  often 
called  by  physicians  a  "whiskey-heart.' 

II.  What  is  the  action  on  the  heart  of  all  ordinary  alcoholic  drinks  ? 
How  is  the  resting  time  of  the  heart  affected  when  its  beat  is  quick- 
ened ?  Result  ?  What  is  fatty  degeneration  ?  Consequence  when 
it  occurs  in  the  heart  ? 


CHAPTER  XV. 
RESPIRATION   OR   BREATHING. 

1.  The  Use  of  Respiration  is  to  renew  the  air  in  the 
lungs.     This  is  necessary  because  the  blood,  as  it  flows 
through   the   lungs,  is   all  the   time    taking   something 
from  the  air  within   them,  and  giving  something  to  it. 
If  this  air  were  not  passed  out,  and  fresh  air  taken  in  its 
stead,  it  would  soon  have  nothing  left  of  what  the  blood 
wants.     It  would  also  become  so  loaded  with  the  waste 
matter  the  blood  gives  off  to  it,  that   it  could   take  no 
more  of  it,  and  so    the   blood  would   not  be   purified. 
Suffocation  is  death  from  want  of  fresh  air  in  the  lungs. 

2.  What  the  Blood  Takes  from  the  Air.— Blood  gets 
nourishment  for  the   body  from   the  alimentary  canal. 
But  we  have  learned   (Chap.  VIII.)  that  in  order  that 
foods  may  give  us  power  and  keep  us  warm,  they  must 
be  oxidized,  and,  clearly,  they  cannot  be  oxidized  unless 
oxygen  is  supplied.     The  blood,  into  which  the  digested 
foods  are  taken,  as  it  flows  through   the  lungs  absorbs 
this  necessary  oxygen. 

3.  What  the  Blood  Gives  to  the  Air.— The  blood  in  its 
passage  through  the   lungs    gives  off  to  the  air,  heat, 

1.  What  is  the  use  of  respiration?     Why  is  it  necessary?    What  is 
suffocation  ? 

2.  Where   does   blood   get  nourishment  for  the   body  ?     Why  is 
oxygen    necessary   as  well   as   food  ?      Where   does   the   blood   get 
oxygen  ? 

3.  What  does  blood  give  to  the  air  as  it  passes  through  the  lungs  ? 


164  CARBONIC  ACID. 

water,  a  gas  named  carbonic  acid,  and  a  small  quantity  of 
organic  matters. 

The  heat  is  easily  recognized  :  you  know  that  your 
breath  is  warm.  The  water  usually  comes  out  in  the 
form  of  invisible  vapor.  On  a  cold  day,  however,  it  is 
seen  as  mist,  streaming  from  the  nostrils  ;  and  any  day 
it  can  be  made  visible  by  breathing  on  a  cold  bright 
object,  as  a  mirror  or  knife-blade. 

The  carbonic-acid  gas  and  the  organic  matters  given 
out  in  the  breath,  are  unfortunately  not  so  easily  made 
apparent  as  the  heat  and  the  water-vapor.  They  are, 
however,  of  very  great  importance.  Carbonic  acid  is 
one  of  the  chief  waste  substances  made  by  the  body 
and  must  be  removed  from  it.  The  organic  matters 
poison  the  body,  if  air  containing  them  be  breathed 
over  and  over  again. 

4.  How  Carbonic  Acid  is  made  from  Charcoal. — You 
remember    that  when    a   human    body  is    incompletely 
burned   (Chap.  I.)   it  forms  a  black  mass  of  charcoal. 
Now  charcoal  is  a  mixture  of  a  substance  named  carbon 
with    some    minerals.     We  may  call   it  impure  carbon. 
When  it  is  burned,  its  carbon  combines  with  oxygen  and 
makes  carbonic-acid  gas.     Just  as  rust  is  oxidized  iron, 
so  carbonic  acid  is  oxidized  carbon  ;   though  it  is  a  gas, 
instead  of  being  solid  like  iron-rust. 

5.  How  Carbonic  Acid  is  made  in  our  Bodies. — All  our 
organs    contain    animal  matter  (p.   10),  and    all   animal 

How  may  the  heat  be  recognized  ?  How  the  water?  Name  a  chief 
waste  matter  produced  by  the  body.  What  is  the  result  of  frequently 
breathing  air  containing  organic  matters  given  out  in  the  breath  ? 

4.  What  is  left  when  a  human  body  is  incompletely  burned  ?    What 
is   charcoal?     What  may  we   call   it?     What   happens  when   it   is 
burned  ?     How  does  carbonic  acid  resemble  and  differ  from  iron-rust? 

5.  What  do  all  our  organs  contain  ?    What  do  all  animal  matters 


FORMATION  OF  CARBONIC  ACID  IN  THE  BODY.   1 6$ 

matters  leave  charcoal  when  they  are  partly  burned. 
They  must,  therefore,  contain  carbon.  It  seems  odd 
that  this  should  be  so,  and  yet  that  they  should  not  be 
black  ;  but  carbon  is  not  always  black.  A  diamond  is 
nearly  pure  carbon  ;  and  can,  by  being  heated,  be  changed 
into  ordinary  black  carbon,  and  then  burnt  and  com- 
bined with  oxygen  to  make  carbonic  acid.  Very  few 
substances  which  contain  carbon  combined  with  other 
things,  are  black ;  as,  for  example,  carbonic-acid  gas 
itself,  which  is  quite  colorless.  In  our  organs,  the  carbon 
is  all  combined  with  other  things;  it  only  shows  its  black 
color  when  the  heat  of  the  fire  has  separated  them  from  it. 

As  long  as  we  live,  our  bodies  are  slowly  burning  or 
oxidizing  (Chap.  VIII.).  By  this  burning,  carbonic  acid 
is  produced  from  the  carbon  of  their  organs.  When  we 
work  hard,  a  great  deal  is  made,  and  when  we  are  at  rest 
much  less.  But  even  in  deep  sleep,  oxidation  is  going 
on  inside  our  bodies  all  the  time,  to  supply  animal  heat, 
and  force  or  power  for  every  heart-beat,  and  each  move- 
ment of  breathing.  The  carbonic  acid  produced  by 
oxidation  in  the  body,  must  be  removed.  When  it  is 
abundant,  the  organs  cannot  receive  or  use  the  oxygen 
which  they  need  in  order  to  do  their  work. 

6.  Breathing  Air  which  contains  much.  Carbonic  Acid, 
will  not  Support  Life. — The  more  carbonic  acid  in  the 
air,  the  less  oxygen.  If  there  is  very  much  carbonic 

leave  when  they  are  partly  burned  ?  What  must  they,  then,  contain  ? 
Illustrate  the  fact  that  things  containing  carbon  are  not  always  black. 
In  what  state  does  carbon  exist  in  our  bodies  ?  When  does  it  show 
its  black  color?  What  occurs  as  long  as  we  live?  What  is  produced 
by  the  burning?  Why  is  oxidation  necessary  even  during  deep 
sleep?  Why  must  the  carbonic  acid  produced  in  the  body  be  re- 
moved ? 

6.  How  does  the  presence  of  carbonic  acid  in  air  affect  the  quan- 
tity of  oxygen  ?  What  is  the  consequence  to  life  if  there  is  much  of 


1 66  FUNCTION  OF   THE  LUNGS. 

acid,  there  is  not  enough  oxygen  to  supply  the  needs  of 
the  body  and  maintain  life.  Death  in  such  case  results 
from  suffocation,  which  may  be  more  plainly  named 
oxygen-starvation.  The  "foul  air"  which  is  sometimes 
present  at  the  bottom  of  deep  wells  or  pits,  and  kills 
people  who  incautiously  go  down  them,  does  so  be- 
cause it  contains  much  carbonic  acid.  Carbonic  acid  is 
not  itself  very  poisonous,  but  air  containing  much  of  it 
is  fatal,  because  carbonic  acid  has  taken  the  place  of 
the  necessary  oxygen  ;  and  air  without  plenty  of  oxy- 
gen will  not  support  life. 

7.  Excretion. — The   process   of    removing   its    wastes 
from    the  body,  or   getting   rid    of  things  which   have 
done   their  work   in    it   and   are    no  longer  wanted,  is 
named  excretion.     The  waste  substances  themselves  are 
also  called  excretions.     Organs  which   remove  them  are 
excretory  organs. 

8.  The  Lungs  Perform  a  Double  Duty.— So  far  as  oxygen 
is  concerned,  they  are  organs  for  taking  something  use- 
ful into  the   body,  and  are   receptive  organs.     So  far  as 
carbonic  acid  is  concerned,  they  are  excretory  organs. 

9.  How  the  Air  is  Purified. — Every  living  human  being 
and  every  one  of  the  lower  animals  is  all  the  time  taking 
oxygen  from  the  air  and  giving  carbonic  acid  to  it.     So 
is  every  fire  and  every  burning  candle.     We  may  natu- 
tallyask,  How  is  the  air  kept  fit  to  breathe? 

it  ?    Give  another  name  for  suffocation  ?    Why  may  carbonic  acid  be 
called  a  "  negative  poison"? 

7.  What  is  the  process  of  excretion  ?    What  substances  are  named 
excretions  ?     What  are  excretory  organs  ? 

8.  What  are  the  two  main  duties  of  the  lungs  ? 

9.  How  do  living  animals  and   fires  alter  the  air  ?     What  living 
things  purify  the  air  ?     Name  a  chief  food  of  green  plants.     What  do 
they  do   with   the  carbonic    acid  they  take  from    the  air?     How   do 
animals  and  plants  help  one  another  ? 


RESPIRATORY  ORGANS.  l6/ 

The  air  is  purified  by  plants.  All  green  plants,  when 
in  the  light,  take  up  carbonic  acid  from  the  air.  It  is 
one  of  their  chief  foods.  From  the  carbonic  acid,  they 
pick  out  the  carbon  and  use  it  in  making  starch  and 
sugar  and  oils,  and  other  things.  The  oxygen,  they  give 
back  to  the  air.  Thus  plants  not  only  make  food  for 
animals  but  keep  the  air  fit  for  them  to  breathe;  while 
animals  by  their  breathing  supply  food  for  plants. 

10.  The   Air    inside  the    Lungs  must  be  Frequently 
Changed. — If  the  air  inside  the  lungs  be  not  frequently* 
replaced  by  fresh  air,  it  becomes  so  full  of  carbonic  acid 
that  it  can  take  no  more  from  the  blood;  and  so  poor  in 
oxygen  that  it  cannot  supply  the  blood  with  enough  of 
that  gas.    Dark-colored  venous  blood  comes  to  the  lungs 
by  the  pulmonary  artery  (Chap.  XIII.),  containing  little 
oxygen  and  much  carbonic  acid.     Through  the  thin  walls 
of  the  pulmonary  capillaries,  it  gives  carbonic  acid   to, 
and  takes   oxygen  from,  the  air  inside  the  lungs,  and 
thus,  replenished  and  purified,  is  returned  to  the  left  side 
of  the  heart  to  be  distributed  over  the  body. 

11.  The  Respiratory  Organs  are — (i)  the  lungs,  in  which 
the   blood  is  exposed  to  the  action  of  the  air  ;  (2)  the 
air-passages,  through   which   air   enters    and    leaves    the 
lungs;  (3)  certain    muscles    (muscles  of  respiration),    and 
the  skeleton  of  the  thorax,  which  work  -together  to  al- 
ternately expand  and  contract  the  chest,  and  thus  renew 
the  air  inside  the  lungs. 

10.  What  happens  if  the  air  within  the  lungs  is  not  frequently  re- 
newed ?     What  sort  of  blood  does  the  pulmonary  artery  bring  to  the 
lungs  ?     What  does  this  blood  do  as  it  flows  through  the  pulmonary 
capillaries  ?     What  becomes  of  it  after  leaving  the  lungs  ? 

11.  Name  the  respiratory  organs.     Use  of  the  lungs?     Of  the  air- 
passages?     Of   the    respiratory   muscles   and    the    skeleton   of    the 
chest? 


1 68 


VOICE. 


12.  The  Air-Passages  are  the  nostril-chambers,  the  phar- 
ynx, the  larynx,  the  windpipe 
or  trachea,  the  bronchi,  and 
the  bronchial  tubes.  The  nos- 
trils (Fig.  42)  open  behind, 
into  the  upper  part  of  the 
pharynx.  From  the  front  of 
the  pharynx,  below  the  level 
of  the  root  of  the  tongue, 
"•L  k,  and  above  the  opening  into 
the  gullet,  the  larynx  pro- 
ceeds. Its  opening  is  over- 
hung by  a  sort  of  lid,  e, 
named  the  epiglottis.  This  lid 
shuts  down  when  food  or 
drink  is  passing  through  the 
pharynx,  but  stands  up  at 
other  times. 

13.    The  Larynx  is  the  or- 
gan   in    which    voice  is    pro- 
KIG.  42.— The  mouth,    nose,  and   duced.     The  hard  projection 

pharynx,   with  the  commencement  of 

the  gullet  and  larynx,  as  exposed   by     Jn     front     of    the    neck,    COm- 

a  section,  a  little  to  the  left  of  the  mid- 


dle of  the  head.    «,  vertebral  column; 

b,   gullet;    c,    windpipe;    <r,  epjgl< 

./",  soft  palate;  g,  opening  of  Eusta- 


in3pK;T%>teio£ta;     m°nly    "amed     "  Adam'S    aP~ 
chian  tube;  *,  tongue;  /,   ha?d  palate^     Ple>"  is  Caused  by  the  larynx, 


c  a 
IS  a 


*«,  the  sphenoid  bone  on   the  base  of 
the  skull;  «,  the  fore  part  of  the  skull- 
cavity;  0, /,  $r,  the  turbinate  bones  of     /  7     *-*•  \     T        A      u 
the  outer  side  of  the  left  nostril-cham-     (a,    fc  Ig.     42)     lined      by     mu- 

cous     membrane.      At     one 

place  the  mucous  membrane  is  pushed  in  from  each  side, 
so  that  only  a  narrow  slit  is  left  in  the  middle.     This 

12.  Name  the  air-passages  ?     Into  what  do  the  nostrils  open  be- 
hind ?    Where  does  the  larynx  begin?    What  is  the  epiglottis?    Its  use? 

13.  Name  the  organ  of  voice  ?     What  is  the  larynx  ?    WThat  is  the 
glottis  ?     What  are  the  vocal  cords  ? 


THE  GLOTTIS.  169 

slit  (c,  Fig.  43)  is  named  the  glottis.  The  folds  forming 
its  sides  are  elastic  and  tightly  stretched ;  they  are 
named  the  vocal  cords. 


FIG.  43. — The  interior  of  the  larynx  as  seen  when  viewed  from  above  and  behind, 
through  its  opening  into  the  pharynx,  i,  hyoid  bone,  which  in  life  has  the  root  of 
the  tongue  attached  to  it ;  5,  lower  part  of  the  pharynx  cut  open ;  6,  top  of  the 
gullet ;  8,  9,  10,  the  right  edge  of  the  opening  of  the  larynx;  «,  «',  #",  epiglottis; 
c,  glottis  (the  dotted  lines  leading  from  the  letter  point  to  the  edges  of  the  vocal 
cords);  £',  6',  hollows  in  the  mucous  membrane  of  the  larynx,  above  the  vocal 
cords  ;  fi,  b,  rounded  prominences  of  the  mucous  membrane,  named  the  false 
vocal  cords  :  they  play  no  direct  part  in  the  production  of  voice. 

14.  How  Voice  is  Produced. — Certain  muscles  separate 
the  vocal  cords  and  widen  the  glottis  ;  others  bring  the 

14.  How  do  muscles  alter  the  glottis  ?    What  is  its  state  in  quiet 


TRACHEA   AND  BRONCHIAL    TUBES. 


cords  together  and  narrow  the  glottis.  In  ordinary  quiet 
breathing  the  glottis  is  wide  open,  and  air  passes  through 
it  without  causing  sound.  When  it  is  narrowed,  and  air 
driven  through  it  from  the  lungs,  voice  is  produced. 
The  sounds  produced  in  the  larynx  are  afterwards 
altered,  and  added  to,  in  various 
ways  in  the  throat,  mouth,  and 
nose.  Thus  voice  is  altered  or 
improved  into  speech. 

15.  The  Windpipe  or  Trachea 
(£,  Fig.  44)  is  a  stiff  tube  which 
may  be  easily  felt  in  the  lower 
part  of  the  front  of  the  neck  of 
thin  persons.  In  its  walls  are 
horseshoe  -  shaped  cartilages, 
which  keep  it  open.  The  wind- 
pipe enters  the  thoracic  cavity, 
and  there  divides  into  two  bron- 
chi, one  for  each  lung  (d,  Fig. 
44). 

FIG.    44. — The    larynx,    trachea, 

bronchi,  and  bronchial  tubes,  seen          16.    The     Bronchial      TUDBS. 

from    the  front.      The    right  lung 

(to  the  left   in  the  figure)  has  Each    bronchus,  as    soon  as  it 

been  dissected  away  to  expose  the 

bronchial    tubes.       a     larynx;    /,  enterS  the  lung,  begins  tO  divide, 

windpipe;  d,   right   bronchus:    its  fc>>        & 

branches  are  bronchial  tubes.  Qver    and    Qver    again,     like    the 

trunk  of  a  tree.  The  branches  are  hollow,  and  the  end 
ones  are  very  small  indeed.  They  are  all  named  bronchial 
tubes.  On  the  left  side  of  Fig.  44  the  right  lung  has  been 
cut  away,  so  as  to  show  the  bronchial  tubes. 

breathing  ?  How  is  voice  produced  ?  How  is  voice  converted  into 
speech  ? 

15.  What  is  the  windpipe?     How  is  it  kept  open?     Where  and 
how  does  it  end? 

16.  What  is  said  concerning  the  bronchial  tubes  ? 


THE  LUNGS.  i;i 

17.  The  Lungs  lie  inside  the  thorax,  one  on  each  side 
of  the  heart  (Fig.  2).     They  are  elastic  spongy  masses, 
full  of  tiny  cavities,  named  air-cells.     Into   the  air-cells 
the  smallest  bronchial   tubes  open  (Fig.  45).     Thus  air 
gets    to   them,   ready  to   give 

oxygen  to  the  blood,  and  carry 
off  carbonic  acid  from  it. 

18.  Inspiration  and  Expira- 
tion.—  Breathing   consists   of 
breathing-in    and     breathing- 
out,    turn     and     turn     about. 
Breathing-out  gets  rid  of  air 

Which  has    become  foul   in    the    Magnified  about  twenty  times. 

lungs:  it  is  named  expiration.  Breathing-in  conveys  new 
air  to  the  lungs  in  place  of  that  which  has  been  expired: 
it  is  known  as  inspiration. 

19.  The   Movements  of  the  Chest    alternately  enlarge 
and  diminish  its  cavity.     When  it  is  enlarged,  air  enters 
it ;  when   it  is  diminished,  air  is  driven  out.     We  may 
compare  the  chest  in  this  respect  to  a  pair  of  bellows. 
The  chief  difference  is  that  air  enters  the  bellows  through 
one  aperture,  and  is  driven  out  through  another ;  while 
in  breathing,  air  comes  and  goes  by  the  same  road,  the 
windpipe,  which  answers  to  the  nozzle  of  the  bellows. 

20.  How  the  Chest- Cavity  is  Enlarged  to  cause  Inspira- 
tion.— The   enlargement  of  the  chest  is  brought   about 


17.  Position   of  the  lungs?    Structure?     How  does  air  reach  the 
air-cells  of  the  lungs  ? 

18.  Of  what  does  breathing  consist?     Use  of  breathing-out?     Its 
technical  name  ?     Of  breathing-in  ?     Its  technical  name  ? 

19.  Result    of  the   chest  -  movements  ?     What    happens  when    the 
chest    is  enlarged  ?     Diminished  ?     Illustrate.     What  part  of  the  re- 
spiratory organs  corresponds  to  the  nozzle  of  a  pair  of  bellows  ? 

20.  How  is  the  chest  enlarged  ?     Position  of  the  ribs  in  expiration? 


172 


INSPIRA  TION. 


by  certain   muscles  which  move  the   ribs,  and  by  the 
diaphragm. 

The  ribs  during  expiration  slope  downwards,  the  end 
of  each  attached  to  the  spinal  column  being  higher  than 
the  end  attached  to  the  breast-bone  (Fig.  5).  When  we 
draw  a  breath,  certain  muscles  pull  up  the  front  ends 
of  the  ribs.  When  this  occurs,  the  breast-bone  is  pushed 
farther  away  from  the  back-bone,  and  the  depth  of  the 
chest  between  breast-bone  and  spinal  column  is  in- 
creased. 

That  raising  the  front  end  of  the  ribs  must  push  the 
breast-bone  forwards  may  be  readily  understood  by  ex- 
amining Fig.  46.  In  the  figure,  ab  represents  the  spinal 
column,  and  st  the  breast-bone. 
The  position  of  the  ribs  in  expira- 
tion is  indicated  by  the  rods  c  and 
d ';  their  position  in  inspiration, 
by  the  dotted  lines  c9  and  d' .  It  is 
clear  that  when  the  ribs  are  raised 
the  sternum  must  be  separated 
farther  from  the  back-bone. 

21.  Action  of  the  Diaphragm  dur- 
ing Inspiration.  —  The  diaphragm 
(d,  Fig.  i)  is  a  dome-shaped  muscle, 
with  its  hollow  side  turned  to- 
wards the  abdomen.  When  it 
contracts,  it  flattens,  and  thus  in- 
creases the  chest-cavity.  At  the  same  time,  it  pushes 
down  the  liver,  stomach,  and  intestines.  These  make 

In  inspiration  ?    What  is  the  result  of  raising  the  front  ends  of  the 
ribs? 

21.  Form  of  the  diaphragm  ?     How  altered  when  it  contracts  ?    Re- 
sult as  regards  the  chest?    The  abdomen  ? 


FIG.  46. — Diagram  of  a 
model  to  illustrate  how  the 
chest-cavity  is  increased  from 
before  back  when  the  front 
ends  of  the  ribs  are  raised,  ab 
represents  the  spinal  column; 
st,  the  breast- bone;  c,  d,  the 
ribs  in  expiration;  c',  d',  the 
ribs  in  inspiration. 


EXPIRA  TION. 


173 


room  for  themselves  by  pushing  out  the  soft  front  wall 
of  the  abdomen,  which  therefore  protrudes. 

22.  The  Combined  Action  of  the  Diaphragm  and  of  the 
Muscles  which  Raise  the  Rihs  is  such  as  to  considerably 
increase  the  chest-cavity.  This  is  illustrated  in  Fig.  47. 
In  B  are  shown  the  size  and  form  of  the  thoracic 
cavity,  and  the  position  of  the  diaphragm,  after  an  expi- 


FIG.  47. — Diagrams  showing'  the  form  and  size  of  the  chest  and  abdomen  during 
inspiration,  A,  and  expiration,  B.  C,  chest-cavity;  D,  diaphragm;  E,  spinal  col- 
umn; F,  collar-bone;  6V,  sternum;  A6,  abdomen;  G,  hip-bone;  //,  coccyx. 

ration.     A  represents  the  chest  and  diaphragm  at   the 
end  of  an  inspiration. 

23.  Expiration. — In  expiration,  the  chest-cavity  is  di- 
minished, and  air  driven  out  of  the  lungs.  It  is  ordina- 
rily brought  about  without  muscular  work.  The  mus- 

22.  What  is  the  result  of  the  combined  action  of  the  diaphragm  and 
the.  muscles  raising  the  ribs  during  inspiration  ? 

23.  What  happens  during  expiration?   How  is  it  ordinarily  brought 
about  ?     Explain  ? 


1/4  SNEEZING  AND   COUGHING. 

cles  which  have  pulled  up  the  ribs  and  sternum  (to  cause 
inspiration)  relax,  and  these  bones  fall  back  into  their 
former  places.  The  diaphragm  also  relaxes,  and  the 
liver,  stomach,  and  intestines,  pressing  against  its  under- 
side, then  push  it  up  towards  the  chest.  Thus  the  lungs 
are  squeezed  and  air  driven  out  of  them. 

24.  Sneezing  and  Coughing. — The  mucous  membrane 
lining  the  nose  and  the  larynx  is  very  sensitive.  Any- 
thing irritating-  it  causes  a  peculiar  kind  of  violent  ex- 
piration, calculated  to  drive  a  powerful  blast  of  air 
through  the  air-passages  and  force  away  the  irritant. 
When  the  inside  of  the  nose  is  tickled,  a  sneeze  follows. 
The  irritation  makes  us  first  draw  a  deep  breath,  with- 
out our  willing  it  at  all,  and  in  spite  of  our  will  if  we  try 
to  prevent  it.  Then,  when  the  lungs  are  filled  with  air, 
the  glottis  (p.  169)  is  closed  and  the  chest  compressed. 
Next,  the  glottis  is  suddenly  opened  and  the  compressed 
air  rushes  out  of  the  lungs.  It  is  made  to  go  through 
the  nose,  because  the  root  of  the  tongue  and  the  soft 
palate  are  brought  together,  so  as  to  close  the  opening 
from  the  pharynx  to  the  mouth.  Sneezing  is  a  good 
example  of  the  resemblance  of  our  bodies  in  many  ways 
to  machines,  made  to  do  a  certain  thing  under  certain  cir- 
cumstances. The  control  which  we  have  over  them  by 
our  will  is  not  at  all  complete.  We  can  neither  prevent 
a  sneeze  when  the  nose  is  irritated,  nor  make  even  a 
good  imitation  of  a  real  sneeze  when  it  is  not. 

A  cough  differs  from  a  sneeze,  mainly  in  the  fact  that 
the  air  is  allowed  to  pass  out  through  the  mouth.  Its 
use  is  to  drive  out  anything  irritating  the  larynx. 

24.  What  results  when  the  mucous  membrane  of  nose  or  larynx  is 
irritated  ?  Describe  the  process  of  sneezing  ?  What  may  we  learn 
from  it  ?  Of  coughing  ?  Its  use  ? 


APPENDIX   TO   CHAPTER  XV. 


APPENDIX  TO   CHAPTER  XV. 

1.  A  sheep's  lungs  with  the  windpipe  attached  may  be  readily  ob- 
tained from  a  butcher.     It  is  best  to  secure  them  and  the  heart  all 
together,  as  unless  the  heart  be  carefully  removed  holes  are  apt  to 
be  cut  in  the  lungs. 

2.  Examine  the  windpipe,  and  trace  it  down  to  its  division  into  the 
brondii.       In  the  wall  of  the  windpipe  note   the   horseshoe-shaped 
cartilages  which  keep  it  open,  and  which  are  so  arranged  that  the 
dorsal  aspect  of  the  tube  (which  lies  against  the  gullet)  has  no  hard 
parts  in  it. 

3.  Trace  the  main  right  bronchus  to  its  lung,  and  then,   cutting 
away  the  lung-tissues,  follow  the  branching  bronchial  tubes  through 
the   organ.     Note  the  cartilages  in  their  walls.     In  the  sheep  there  is 
a  small  extra  bronchus  on  the  right  side,  which  goes  to  the  upper 
part  of  the  right  lung.     It  is  not  present  in  man. 

4.  Carefully  divide  the  left  bronchus  where  it  joins  the  windpipe, 
and  lay  it  and  its  lung  aside.     Then  slit  open  the  trachea,  the  bronchus 
still  attached  to  it,  and  the  bronchial  tubes.     Observe  the  soft  pale-red 
mucous  membrane  lining  them. 

5.  In  the  left  bronchus,  which  has  still  an  uninjured  lung  attached 
to  it,  tie  air-tight  a  few  inches  of  glass  tubing  of  convenient  size. 
On  the  end  of  the  glass  tube  then  slip  a  few  inches  of  rubber  tubing. 
On  blowing  through  the  rubber  tube  the  lung  will  be  distended,  and 
as  soon  as  the  opening  is  left  free  it  will  collapse;  in  this  way  its 
great  extensibility  and  elasticity  will  be  seen. 

6.  Blow  up  the  lung  moderately,  and  while  it  is  distended  tie  a 
string  very  tightly  around  the  bit  of  rubber  tubing.     This  will  keep 
the  air  from  escaping;  the  distended  lung  can  now  be  examined  at 
leisure,  and  its  form,  lobes,  and  the  smooth  moist  pleura  covering  it 
be  better  seen  than  when  it  is  collapsed. 

7.  The  diaphragm  may  be  readily  seen  in  the  body  of  any  small 
animal  (rat,  kitten,  puppy),  on  removing  the  abdominal  viscera.    The 
liver  and  stomach  must  be  cut  away  with  especial  care. 

a.  When  the  above  viscera  are  removed,  the  vaulted  diaphragm  will 
be  seen,  and  through  it  the  pink  lungs. 

b.  Pull  the  diaphragm  down,  imitating  its  contraction  and  flattening 
in  inspiration.    The  lungs  will  be  seen  to  follow  it  closely,  expanding 
to  fill  the  space  left  by  it  in  its  descent. 

c.  Make  a  free  opening  into  one  side  of  the  thorax.     The  corre- 
sponding lung  will  collapse,  and  be  no  longer  influenced  by  move- 
ments of  the  diaphragm. 

d.  Now  open  the  other  side  of  the  chest:  its  lung  also  shrinks  up; 
the  structure  of  the  diaphragm  (its  tendinous  centre  and  muscular 
sides)  can  now  be  better  seen,  as  also  the  attachment  of  the  pericar- 
dium to  its  thoracic  side. 


CHAPTER  XVI. 
HYGIENE  OF  RESPIRATION. 

1.  Introductory. — We  all  know,  of  course,  that  air  which 
is  not  fresh  is  unpleasant  to  breathe,  but  many  persons 
appear  not  to  know  that  it  is  also  poisonous. 

Suppose  you  put  an  air-tight  bag,  containing  two  or 
three  pints  of  air,  close  to  your  mouth,  and  kept  your 
nostrils  closed,  so  that  no  air  could  enter  the  lungs  but 
that  in  the  bag.  For  the  first  few  breaths  you  would 
have  no  trouble.  But  after  you  had  breathed  in  and  out 
of  the  bag  several  times  the  air  within  it  would  not  have 
enough  oxygen  left  to  supply  the  needs  of  the  body,  and 
would  be  so  full  of  excretions  as  to  be  poisonous. 

If  you  want  to  keep  a  pet  puppy  or  kitten  in  a  box, 
you  make  an  air-hole.  When  asked  why,  you  reply  that 
the  animal  would  die  without  air,  yet  there  is  already  in 
the  box  as  great  a  quantity  of  air  as  could  get  in  if  there 
were  dozens  of  holes.  What  you  want  is  to  give  your 
pet  fresh  air  from  the  outside  so  that  it  will  not  have  to 
breathe  over  and  over  again  that  which  becomes  more 
poisoned  every  time  the  animal  draws  it  into  his  lungs. 
When  we  shut  ourselves  up  in  rooms  with  tight  win- 

i.  What  is  said  of  air  that  is  not  fresh  ?  How  is  air  altered  every 
time  it  is  breathed  ?  What  would  happen  if  you  tried  to  go  on  breath- 
ing the  air  shut  up  in  a  small  bag  ?  What  is  the  real  reason  that  an 
animal  shut  up  in  a  box  needs  an  air-hole?  Apply  to  closed  rooms, 


STARVATION  AND   SUFFOCATION.  I// 

dows  and  no  open  fireplaces,  we  are  as  badly  off  as  the 
puppy  would  be  in  his  box,  without  an  air-hole,  if  you 
should  occasionally  open  and  shut  the  lid  quickly,  as 
we  do  our  doors  on  a  cold  day. 

2.  Starvation  and  Suffocation  Compared. — If  a  man  gets 
no  food,  he  soon  dies  of  starvation.  If  he  gets  some  food, 
but  not  enough  for  the  needs  of  his  body,  he  lives  longer, 
but  his  whole  body  is  weak.  At  last  he  dies  of  slow 
starvation,  unless  some  disease  attacks  his  feeble  organs, 
and  kills  him  before  want  of  nourishment  has  had  time 
to  do  so, 

It  is  much  the  same  as  regards  the  supply  of  oxygen 
in  the  air  we  breathe.  If  there  is  no  oxygen  in  it,  death 
takes  place  in  a  few  minutes.  Death  from  suffocation 
occurs  quicker  than  death  from  starvation,  because  our 
bodies  have  laid  up  in  them  but  very  little  more  oxygen 
than  they  need  at  the  moment;  whereas,  in  fat  and  some 
other  tissues,  there  is  a  store  of  nourishing  matter  which 
the  body  can  make  use  of  when  its  food  is  not  enough. 
Fat,  when  not  present  in  such  excess  as  to  hamper 
various  organs  in  their  work,  may  be  compared  to  a 
little  money  laid  by  in  a  savings-bank,  and  ready  for  use 
in  case  the  regular  supply  gives  out.  There  is  no  such 
bank  in  our  bodies  where  extra  oxygen  can  be  stored. 
In  health,  the  blood  and  each  organ  possess  just  a  little 
more  than  they  want  at  the  moment,  but  that  is  all.  It 
is  like  a  few  cents  of  pocket-money,  which  does  not  last 
long  if  we  have  to  live  on  it. 

2.  What  happens  if  a  man  does  not  get  enough  food  ?  Of  what 
does  he  die  ?  If  he  gets  no  oxygen  ?  Why  does  a  man  die  of  suffo- 
cation sooner  than  of  starvation  ?  To  what  may  fat  be  compared  ? 
How  much  oxygen  do  the  blood  and  organs  possess  in  health  ?  To 
what  compared  ? 


178  RESULTS  OF  BREATHING  FOUL  AIR. 

3.  Foul  Air  is  Worse  than  Insufficient  Food. — If  a  man 
be  nearly  starved  to  death  and  then  be  carefully  nour- 
ished, he  may  soon  be  all  right  again,  but  if  he  has  been 
slowly  poisoned,  as  well  as  starved,  he  is  not  so  likely  to 
recover.  When  a  man  does  not  get  enough  fresh  air  to 
breathe,  he  is  not  only  starved  for  want  of  oxygen,  but 
poisoned.  The  wastes  or  excretions  of  the  foul  air  are 
absorbed  into  the  blood  from  the  lungs,  and  are  then 
carried  by  the  blood  to  every  organ.  The  health  of  the 
body,  when  pure  air  is  breathed,  depends  on  the  perfec- 
tion with  which  the  blood  carries  oxygen  to  every  nook 
and  corner.  When  impure  air  is  breathed,  the  hurtful 
substances  taken  into  the  blood  as  it  flows  through 
the  lungs,  are  carried  in  exactly  the  same  way  to  all 
parts. 

You  know  that  there  are  quick  poisons  and  slow 
poisons.  Quick  poisons  kill  in  a  few  minutes  or  a  few 
hours.  Slow  poisons  may  not  kill  for  weeks,  months, 
or  even  years.  Many  slow  poisons  do  not  themselves 
actually  cause  death,  but  they  so  much  weaken  some  of 
the  organs  that  the  body  is  very  apt  to  take  disease,  and 
in  its  feeble  condition  cannot  master  and  overcome  it. 
Foul  air  is  rarely  foul  enough  to  act  as  a  quick  poison, 
but  unless  proper  care  be  taken,  the  air  in  rooms  much 
lived  in,  soon  becomes  foul  enough  to  act  as  a  slow 
poison.  How  quick  or  how  slow,  depends  simply  on  how 
foul  the  air  may  be. 

3.  What  is  the  usual  result  if  a  man  be  carefully  fed  after  being 
nearly  starved  to  death?  If  he  has  been  also  poisoned?  Apply  to 
want  of  sufficient  fresh  air.  How  are  the  poisonous  matters  in  foul 
air  carried  over  the  body? 

What  are  quick  poisons  ?  Slow  ?  How  do  many  slow  poisons  act  ? 
What  is  said  of  foul  air  as  a  quick  and  a  slow  poison  ? 


DEATH  FROM  WANT  OF  FRESH  AIR.  IJg 

4.  Rapid  Death  from  Insufficient  Supply  of  Fresh  Air. — 

Cases  of  quick  poisoning  from  repeated  breathing  of  the 
same  air  are  not  frequent  Fortunately,  few  doors  and 
windows  fit  so  tight  as  to  prevent  fresh  air  from  getting 
into  a  room,  and  foul  air  out  of  it,  fast  enough  to  keep  one 
or  two  people  alive.  The  very  deadly  result  of  breathing 
the  same  air  repeatedly  has,  however,  been  terribly 
proved  in  more  than  one  instance.  The  steamship 
"  Londonderry,"  a  few  years  ago,  sailed  from  Liverpool 
with  two  hundred  passengers  on  board.  Stormy  weather 
coming  on,  the  captain  ordered  all  the  passengers  into  a 
small  cabin  and  then  closed  its  openings.  "  The  wretched 
passengers  were  now  condemned  to  breathe  over  and 
over  again  the  same  air.  This  soon  became  intolerable. 
There  occurred  a  horrible  scene  of  frenzy  and  violence, 
amid  the  groans  of  the  dying  and  the  curses  of  the  more 
robust.  This  was  stopped  by  one  of  the  men  contriving 
to  force  his  way  on  deck,  and  to  alarm  the  mate,  who 
was  called  to  a  fearful  spectacle.  Seventy-two  were 
already  dead  and  many  were  dying  ;  their  bodies  were 
convulsed,  the  blood  starting  from  their  eyes,  nostrils, 
and  ears."  All  this  occurred  within  six  hours. 

Not  merely  some  fresh  air,  but  a  certain  quantity  of 
fresh  air  is  necessary  to  maintain  life.  It  seems  almost 
absurd  to  point  out  this  fact,  yet  many  folks  act  as  if  they 
believed  that  any  air-hole,  with  little  regard  to  its  size, 
were  sufficient.  The  greater  the  number  of  people  in  a 
room,  the  more  abundant  must  the  air-supply  be. 
Ignorance  of  this  fact  led  to  the  horrible  catastrophe  of 

4.  Why  is  quick  poisoning  from  foul  air  not  frequent  ?  Give  an  ac- 
count of  the  example  of  it  on  board  the  "  Londonderry."  What  be- 
sides "  some"  fresh  air  is  needful  ?  When  must  the  fresh  air  be  more 
abundant?  Describe  the  catastrophe  of  the  "  black  hole  of  Calcutta.'1 


1 80  VEN  TIL  A  TION. 

the  "  black  hole  of  Calcutta."  One  hundred  and  forty- 
six  prisoners  were  shut  up  in  a  small  room  with  two 
narrow  open  windows.  These  windows  would  probably 
have  supplied  abundant  fresh  air  for  ten  or  twenty  per- 
sons, but  they  were  so  insufficient  for  the  needs  of  the 
large  number  locked  up  in  the  room,  that,  in  eight 
hours,  one  hundred  and  twenty-three  died. 

5,  Ventilation. — Most  of  us  have  to  spend  a  large  part 
of  our  time  within  more  or  less  closed  rooms.     In  order 
that  the  air  in  them   may  continue  fit  to  breathe,  it  must 
be  changed  all  the  time.     This  removal  of  the  foul  air 
and    its    replacement    by    fresh,  is  known  as    ventilation. 
Ventilation  is  "sufficient"  when  it  renews  the  air  fast 
enough.     It  is  good  when,  in  addition  to  being  sufficient, 
it  does   not  cool  a  room   too  much   or  cause   injurious 
draughts. 

6.  The  Amount  of  Ventilation    Necessary  depends  of 
course  on  many  things.     If  there  are  two  people  living 
in  a  room,  they  will  require  just  twice  as   much  fresh  air 
as  one;  and  fifty  will  need  fifty  times  as  much.     School- 
rooms, churches,  theatres,  and  other  like  places,  where 
many  people  collect,    need    very  free  ventilation.      All 
such  burning  things   as  fires   or  candles  or  gas  or  oil- 
lamps,    take   valuable    oxygen    from    the   air   and    give 
hurtful  carbonic  acid  to  it.    In  ventilating  a  room,  allow- 
ance must  therefore  be  made  for  them.     Ventilation  just 


5.  What  is  necessary  that  the  air  in  inhabited  rooms  may  continue 
fit  to  breathe  ?     What  is  ventilation  ?     Sufficient  ventilation  ?     Good 
ventilation  ? 

6.  How  does  the  number  of  persons  in  a  room  affect  the  amount  of 
ventilation   necessary  ?     Examples  of   rooms   which   especially  need 
free   ventilation?     How  do  burning   things   alter  the   air?     Why   is 
more  ventilation  necessary  when  the  gas  is  lighted  ? 


CONSEQUENCES  OF  DEFICIENT    VENTILATION.     l8l 

sufficient  in   the  morning,  will  not  be  enough  at  night 
when  the  gas  is  lighted. 

7.  How  Deficient  Ventilation  may  be  Recognized. — The 
nose  generally  affords   the  most  sensitive  as  well  as  the 
most  convenient  test  of  the  sufficiency  of  the  ventilation 
of  an  inhabited  room.       If   ill   ventilated,  the   air  will 
usually  smell   "  close."     Those   who   have   been    in  the 
room  for  some  time  are  not  likely  to  realize  how  foul  the 
air  has  become,  as  the  nose  gradually  gets  used  to  air 
around  it,  which  would  be  extremely  unpleasant  to  one 
just  entering   the   room.     If  the  room  smells  even  the 
least  bit   "  close"  to  a  person  entering  it  from  out  of 
doors,  it  needs  more  ventilation. 

8.  Consequences  of  Living  in  Insufficiently  Ventilated 
Rooms. — A  stay  of  an  hour  or  two  in  a  room  not  supplied 
with  enough  fresh  air,  results  in  headache,  dulness,  and 
sleepiness,    which    soon  go  off  when  we  get   out  again 
into  the  fresh  air.     Children  have  often  been  punished 
for  seeming  neglect  of  their  studies,  when  the  foul  air  of 
the  school-room  was  really  to  blame. 

If  one  spends  a  considerable  portion  of  every  day  in  a 
badly  ventilated  room,  the  whole  body  is  enfeebled.  The 
blood  becomes  poor  in  red  corpuscles,  and  the  face  pale; 
appetite  is  lessened,  digestion  imperfect,  and  the  muscles 
weak.  The  body,  not  getting  enough  oxygen  and  being 
at  the  same  time  slowly  poisoned  by  breathing  its  own 
wastes  over  and  over,  has  but  little  reserve  force.  It  is 


7.  How  does  the  air  of  an  ill-ventilated  room   affect  the   nose  ? 
Why  may  foul  air  not  be  perceived  by  those  who  have  been  some 
time  in  an  insufficiently  ventilated  room  ?     When  does  a  room  need 
more  ventilation  ? 

8.  What  are  the  consequences  of  staying  for  an  hour  or  two  in  a 
badly  ventilated  room?    What  of  spending  several  hours  daily  in 


1 82  EFFECTS  OF   TIGHT  LACING. 

liable  to  take  disease,  and  when  disease  occurs,  there  is 
less  chance  of  recovery. 

Consumption  and  other  lung-diseases  are  especially 
frequent  in  persons  who  live  in  badly  ventilated  rooms. 
So  are  colds  of  all  kinds. 

9.  Free  Chest-Movements  are  Necessary  for  Healthy 
Breathing. — Plenty  of  fresh  air  to  breathe  is  not  of  much 
use  if  the  chest  is  so  imprisoned  that  it  cannot  expand 
properly.  No  garment  which  checks  the  free  movements 
of  thorax  and  abdomen  in  breathing,  should  be  worn. 
The  tight  lacing  which  used  to  be  thought  elegant,  and 
is  still  indulged  in  by  some  who  think  a  distorted  form 
beautiful,  does  harm  in  many  ways.  In  the  first  place  it 
makes  all  healthy  exercise  impossible.  A  tightly  laced 
person  gets  "  out  of  breath "  on  the  least  exertion. 
Many  a  woman  complains  that  she  is  unable  to  attend  to 
her  household  duties,  because  the  least  exertion  fatigues 
her,  when  all  that  is  the  matter  is  that  she  has  so  laced 
her  chest  that  it  cannot  do  its  breathing  work  properly. 
Tight  lacing  also  hampers  the  abdominal  organs.  It  so 
narrows  the  chest  (Fig.  12)  that  lungs  and  heart  are 
pushed  down  towards  the  abdomen,  to  get  room.  The 
heart  is  driven  so  close  against  the  stomach  that  even  a 
moderate  meal  is  apt  to  press  unnaturally  against  it 
(p.  127),  and  so  its  working  is  interfered  with.  The 
livers  of  those  who  have  practised  tight  lacing  are  often 
found  to  have  hard  unhealthy  cords  on  them,  caused  by 
pressure  from  the  lower  ribs,  squeezed  in  by  the  corset. 

badly  ventilated  rooms  ?  What  diseases  are  especially  frequent  in 
those  who  live  in  ill-ventilated  rooms? 

9.  What  is  necessary  for  healthy  breathing,  besides  pure  air  ?  How 
does  tight  lacing  do  harm  as  regards  exercise  and  work  ?  As  regards 
the  heart?  As  regards  the  liver ? 


EXPANSION  OF  CHEST  BY  EXERCISE. 


183 


10.  Expansion  of  the  Chest  by  Exercise. — Some  persons 
are  born  with  narrow  chests,  and  are  predisposed  to  lung- 
diseases.  Proper  exercise,  regularly  performed,  will  do 
a  great  deal  to  widen  the  chest.  Rowing  is  good  for 


FIG.  48. 


FIG.  49. 


FIG.  48. — Part  of  the  celebrated  statue  known  as  the  u  Venus  of  Milo,"  a  recog- 
nized standard  of  female  beauty. 
FIG.  49. — The  dressmaker's  idea  of  a  beautiful  waist. 

this  purpose,  but  certain  gymnastic  exercises  are  better. 
They  often  increase  the  size  of  the  thorax  even  in  a  few 
weeks.  A  delicate  person  should  get  skilled  advice  as  to 
the  kind  and  amount  of  work  to  do  in  a  gymnasium. 
Otherwise  he  may  easily  do  himself  harm. 


10.   How  may  the  chest  be  made  larger?    What  should  a  delicate 
person  do  before  beginning  work  in  a  gymnasium  ?     Why  ? 


1 84    ACTION  OF  ALCOHOL  ON  RESPIRATORS  ORGANS. 

11.  Mouth-Breathing. — Quite     a    number    of    people 
breathe   through   the  mouth  instead  of  the  nose.     This 
not  only  gives  the  face  a  weak  silly  look,  but  it  tends  to 
cause  disease  of  the  lungs  and  air-passages. 

When  air  is  breathed  through  the  nose,  it  has  to  pass 
through  a  long  narrow  passage  lined  with  warm  moist 
mucous  membrane,  before  it  gets  into  the  pharynx.  In 
this  way  it  is  warmed  and  moistened  before  it  enters  the 
larynx,  on  its  way  to  the  lungs.  Air  breathed  in  through 
the  mouth  is  apt  to  be  too  cold  or  too  dry  when  it  reaches 
the  bronchial  tubes,  and  to  injure  them  and  the  air-cells 
of  the  lung. 

The  nostrils  are  very  often  blocked  during  a  cold  in 
the  head,  but  if  your  nostrils  are  usually  so  stopped 
that  you  find  difficulty  in  breathing  through  them  they 
should  be  examined  by  a  physician,  in  order  that  what- 
ever causes  the  stoppage  may  be  removed.  If  a  child 
habitually  breathes  through  the  mouth  when  asleep,  it 
is  probable  that  something  is  wrong  with  its  nose. 

12.  Action    of   Alcoholic    Drinks    on    the    Respiratory 
Organs. — Indulgence  in  alcoholic  drinks  often  keeps  the 
mucous  membrane  lining  the  air-passages  in  a  congested 
state.     It  thus  increases  the  tendency  to  colds  of  the 
head  and  chest.     There  is  also  a   peculiar  form  of  con- 
sumption  of  the  lungs,   which  is   rapidly  fatal,  and  is 
found  only  in  drunkards. 

ir.  What  must  air,  when  breathed  through  the  nose,  do  before  it 
reaches  the  pharynx  ?  What  results  ?  Why  is  air  breathed  in  through 
the  mouth  likely  to  injure  the  lungs  ?  What  should  be  done  if  you 
have  continual  difficulty  in  breathing  through  the  nose  ? 

12.  Action  of  alcohol  on  the  air-passages  ?  Results  ?  What  lung- 
disease  is  found  specially  in  drunkards? 


CHAPTER   XVII. 
THE   KIDNEYS  AND   THEIR   FUNCTION. 

1.  Why  the  Kidneys  are  Needed. — We  have  seen  how 
the  body  gets  rid   of   one  of    its  chief   waste  matters, 
namely,    carbonic    acid.      Another    waste    substance    is 
formed  in  it  every  day  in  large  quantity,  and  if  not  car- 
ried out  would  do  just  as  much  harm  as  carbonic  acid. 
This  waste  substance  is  named  urea.     It  is  solid,  and  so 
cannot  be  separated  by  the  lungs,  which  can  pass  out 
gases  and  vapors.     The  urea  is  removed  by  the  kidneys, 
along  with  a  great  deal  of  water  in  which  it  is  dissolved; 
it  is  thus  passed  out  in  a  liquid  form. 

Urea  contains  nitrogen,  and  is  produced  when  albu- 
mens are  oxidized  (p.  83),  or  used  up,  in  doing  their 
work  in  the  body. 

2.  The  Renal  Organs  include  not  merely  the  kidneys, 
but  the  apparatus  by  which  their  secretion  is  carried  to 
the  outside  of  the  body  and  expelled  from  it.    They  are: 

(1)  the  kidneys,  two  large  glands  placed  in  the  abdomen; 

(2)  the  ureters,  or  the  ducts  (p.  66),  of  the  kidneys,  which 
carry  the  secretion  to  (3)  a  reservoir,  the  bladder,  where 
it  collects.    The  bladder  is  a  muscular  bag.    It  contracts 

1.  What  is  urea?     Why  can  it  not  be  separated   by  the    lungs? 
What  organs  remove  it  ?    In  what  form  ?     What  does  urea  contain  ? 
How  is  it  produced  ? 

2.  What  do  the  renal  organs  include?    Name  them.     Function  of 
ureters?     Of  bladder?    Of  urethra?     When  do  the  kidneys  work ? 


i86 


FIGURE  OF  RENAL  ORGANS. 


UA 

FIG.  50.— The  renal  organs,  one-third  life  size,  viewed  from  behind.  A,  lower  end 
of  aorta;  Ar,  the  right  renal  artery;  /?,  the  right  kidney;  £/,  the  right  ureter;  K«, 
the  bladder;  t/a,  commencement  of  urethra;  Fr,  lower  end  of  inferior  vena  cava; 
Vr,  the  right  renal  vein. 


COMPARISON  OF   THE  EXCRETORY  ORGANS,     l/ 

from  time  to  time  and  expels  the  liquid  which  has  gath- 
ered in  it,  through  a  passage  (4)  named  the  urethra.  The 
kidneys  are  at  work  all  the  time,  separating  urea  from 
the  blood,  though  the  bladder  only  empties  out  their 
secretion  a  few  times  a  day. 

3.  The  Kidneys  lie  at  the  back  of  the  abdominal  cavity, 
on  the  sides  of  the  vertebral  column,  a  short  way  below 
the  diaphragm.     Each  is  about  half  as  big  as  its  owner's 
clenched  fist.     The  blood  is  sent  to  the  kidneys  for  purifi- 
cation by  two  large  branches  of  the  aorta,  named  the 
renal  arteries.     The  kidneys  not  only  take  urea  from  the 
blood,  but  help  in  removing  other  waste  matters. 

4.  The  Chief  Excretory  Organs   Compared  as  to  their 
Functions. — The  skin  gets  rid  of  a  good  deal  of  water,  of 
some  mineral  matters  which  have  done  their  work,  and 
sometimes  of  a  little  urea.     The  duties  of  the  skin  as  an 
excretory  organ   are   important,  and   health   cannot  be 
maintained  if  they  are  badly  performed.     But  the  chief 
functions  of   the  skin  are   to   protect  deeper  parts,  to 
regulate  the  temperature  of   the  body  (p.  77),  and  to 
give  us  the  sense  or  feeling  of  touch  (Chap.  XXL). 

The  lungs  get  rid  of  much  carbonic  acid,  of  small  quan- 
tities of  very  poisonous  animal  vapors,  and  of  some  water. 
They  separate  no  mineral  wastes  and  no  urea.  The  func- 
tion of  the  lungs  as  receptive  organs,  to  supply  the  body 
with  oxygen,  is  as  important  as  their  excretory  function. 

The  kidneys  are  solely  excretory  organs.    To  get  rid  of 


3.  Position  of  the  kidneys  ?    Size  ?    How  is  blood  carried  to  them  ? 
What  do  they  do  besides  taking  urea  from  the  blood  ? 

4.  What  is  said  of  the  skin  as  an  excretory  organ  ?     Of  its  other 
functions?     Of  the  lungs  as  excretory  organs  ?     Of  their  other  duty  ? 
Of  the  duty  of  the  kidneys  ?     What  do  the  kidneys  remove  from  the 
body  ? 


1 88  HYGIENE   OF   THE  KIDNEYS. 

waste  matters  which  would  poison  the  body  is  their  only 
duty.  Except  a  very  little  carried  off  by  the  skin,  they 
remove  all  the  waste  matters  containing  nitrogen,  a 
great  deal  of  water,  nearly  all  the  mineral  wastes,  and 
some  carbonic  acid. 

5.  Hygiene   of  the  Kidneys.— If  both  kidneys  be  cut 
out  of  an  animal,  it  dies  in  a  few  hours  from  blood-poison- 
ing, caused  by  the  wastes  which    have  collected  in   it. 
Serious  kidney-disease  amounts  to  pretty  much  the  same 
thing  as  cutting  out  the  organs,  since  they  are  of  little 
use  if  not  healthy.     It  is  always  fatal  if  not  checked,  and 
often  kills  in  a  short  time.     The  things  which  most  fre- 
quently cause  kidney-disease  are  undue  exposure  to  cold, 
and  indulgence  in  alcoholic  drinks. 

6.  Cold  Causes  Kidney-Disease  partly  by  driving  blood 
from  the  surface  and  congesting  the  kidneys,  partly  by 
throwing  too  much  work  on  them.     When  the  skin  does 
not  get  rid  of  its  proper  share  of  the  waste  matters  of 
the  body,  it  is  chiefly  the  kidneys  which  have  to  make  up 
for  it. 

Nearly  all  the  infectious  diseases  which  are  accom- 
panied by  a  rash  on  the  skin,  as  measles  and  scarlet  fever, 
also  affect  the  kidneys.  During  these  diseases,  the  kid- 
neys are  more  or  less  inflamed,  and  in  the  early  stages  of 
recovery  they  are  still  weak  and  easily  injured.  Under 
these  circumstances,  exposure  to  cold  is  very  apt  to  cause 
incurable  kidnev-disease. 


5.  What  is  the  consequence  of  removing  the  kidneys?     Of  kidney- 
disease  ?    How  is  serious  disease  of  the  kidneys  most  often  produced  ? 

6.  How  does  cold  injure  the  kidneys?   When  have  they  to  do  the 
work  of  the  skin  ?    What  diseases  especially  affect  them  ?    State  of  the 
kidneys  during  recovery  from  these  diseases?     Precautions  to  be 
taken  ? 


ACTION   OF  ALCOHOL    ON    THE  KIDNEYS.       189 

7.  Alcohol  Causes  Kidney-Disease  in  Several  Ways. — In 
the  first  place  it  overstimulates  the  organs.  Next,  when 
its  abuse  is  continued,  it  interferes  with  the  proper  prep- 
aration of  the  nitrogen  wastes:  they  are  then  brought 
to  the  kidneys  in  an  unfit  state  for  removal,  and  injure 
those  organs.  Third,  when  more  than  a  small  quantity  of 
alcohol  is  taken,  some  of  it  is  passed  out  of  the  body  un- 
changed, through  the  kidneys,  and  injures  their  substance. 

The  kidney-disease  most  commonly  produced  by  alco- 
hol, is  one  kind  of  "Bright's  disease,"  so  called  from 
the  physician  who  first  described  it.  The  connective 
tissue  of  the  organ  grows  in  excess,  and  the  true  excreting 
kidney-substance  dwindles  away.  At  last  the  organ  be- 
comes quite  unable  to  do  its  work,  and  death  results. 

7.  State  one  effect  of  alcohol  on  the  kidneys.  Another?  A  third? 
What  kidney-disease  is  commonly  produced  by  alcoholic  excess  ?  How 
are  the  kidneys  altered  by  it?  Results? 


APPENDIX  TO   CHAPTER  XVII. 

To  demonstrate  the  anatomy  of  the  renal  organs  proceed  as  follows: 

1.  Kill  a  rat,  puppy,  or  kitten  in  any  merciful  way;  placing  it  under 
a  bell-jar  with  a  sponge  soaked  in  ether  is  a  good  method. 

2.  Open  the  abdomen  of  the  animal,  remove  its  alimentary  canal, 
and  cut  away  (with  stout  scissors)  the    front   of    the    pelvic   girdle. 
The  dark  red  kidneys  will  then  be  easily  recognized  on  each  side  of 
the  dorsal  part  of  the  abdominal  cavity,  the  right  one  nearer  the  head 
than  the  left. 

3.  Dissect  away  neatly  the  connective  tissue,  etc.,  in  front  of  the 
vertebral  column,  so  as  to  clean  the  inferior  vena  cava  and  the  abdomi- 
nal aorta.     Trace  out  the  renal  arteries  and  veins. 

4.  Find  the  ureter,  a  slender  tube  passing  back  from  the  kidney 
towards  the  pelvis:  it  leaves  the  inner  border  of  the  kidney  behind 
the  vein  and  artery;   and  lying,  at  first,  at  some  distance  from  the 
middle  line,  converges  towards  its  fellow  as  it  passes  back. 

5.  Follow  the  ureters  back  until   they  reach  the  urinary  bladder; 
dissect  away  the  tissues  around  the  latter  and  note  its  form,  etc. 

6.  Open  the  bladder;  find  the  apertures  of  entry  of  the  ureters, 
and  pass  bristles  through  them  into  those  tubes.     Note  the  mucous 
membrane  lining  the  bladder. 


CHAPTER   XVIII. 
THE    NERVOUS    SYSTEM    AND    ITS    FUNCTIONS. 

1.  Introductory. — If  the  inside  of  your  nose  be  tickled, 
you    cannot    help     sneezing ;     it    seems    so    natural    to 
sneeze  when  anything  irritates  the  nostrils  that  probably 
you  never  thought  about  it  at  all.     But  if  you  do  think 
about  it,  you  will  find  that  it  is  something  quite  curious 
and  interesting.     If  some  one  puts  a  soft  feather  up  your 
nose,  neither  the   larynx,  nor  the  lungs,  nor  the  chest- 
muscles,   nor   the    diaphragm,  are  interfered  with;    yet 
they  all  (p.  174)  set  to  work  at  once  to  help  the  nose  to 
get  rid  of  what  is  worrying  it,  and  they  do  this  without 
paying  any  heed  to  your  will.     In  other  words,  they  act 
involuntarily.     They  do,  apparently  of  themselves,  what 
is  likely  to  help  the  nose,  and  they  set  to  work  in  a  very 
orderly  way.     If  any  one  of  them  failed  to  do  its  share 
of  the  work,  or  worked  never  so  little  out  of  its  turn,  no 
useful  sneeze  would  be  produced. 

How  the  nose  obtains  such  ready  and  well-planned 
help  from  all  these  organs  which  lie  at  a  distance  from 
it,  we  will  try  in  this  chapter  to  explain. 

2.  Other  Examples  of  the  Help  which  our  Organs  give 
to  One  Another. — Coughing   (p.  174)  is   one  that   will  of 

i.  What  results  from  irritating  the  inside  of  the  nostrils?  What 
organs  work  together  to  produce  a  sneeze  ?  What  is  meant  by  say- 
ing that  they  act  "  involuntarily  "  ?  What  would  happen  if  any  one 
of  them  did  not  act  "just  right"  ? 


THE  MUTUAL  HELP   OF  DIFFERENT  ORGANS.    IQI 

course  come  to  your  nnind  at  once.  There  are  others 
that  you  may  think  of,  as  you  have  also  learned  that 
when  you  exercise  your  muscles,  the  heart  and  lungs 
work  more  vigorously  to  supply  them  with  sufficient 
nourishment  and  oxygen,  and  to  carry  off  their  extra 
wastes;  that  when  the  air  is  cold,  the  blood-vessels  of 
the  skin  contract  and  drive  blood  away  from  the  surface 
to  prevent  too  rapid  cooling  (p.  178);  that  when  your 
body  is  hot,  the  sweat-glands  become  very  active  so  as  to 
cool  the  blood,  and  through  it  the  internal  organs(p.  67); 
that  when  partly  digested  food  passes  from  the  stomach 
into  the  small  intestine,  the  gall-bladder  at  once  squeezes 
out  bile  (p.  n6)tobe  mixed  with  it,  and  help  the  intes- 
tine in  digestion  and  absorption. 

All  of  the  things  above  mentioned  are  done  without 
our  will,  and  some  of  them  even  without  our  being 
aware  when  they  take  place,  as  the  pouring  of  bile  into 
the  small  intestine.  They  are  but  a  few  examples  out 
of  hundreds,  which  show  that  our  organs  work  together 
for  the  good  of  the  whole  body,  and  often  help  one  an- 
other without  our  planning  it,  or  our  minds  having  any- 
thing to  do  with  it.  Very  clearly  there  must  be  some 
means  by  which  the  various  organs  are  made  to  work  in 
such  harmony. 

3.  The  Nervous  System. — When  we  try  to  imagine  how 
each  organ  might  be  put  in  communication  with  all  the 
others,  probably  the  first  idea  that  comes  to  mind  is  that 

2.  Of  what  is  coughing  an  example  ?     How  do  the  heart  and  lungs 
help  the  muscles  during  exercise  ?     How  do  the  blood-Tessels  of  the 
skin  keep  the  rest  of  the  body  from  being  too  much  cooled  ?    How  do 
the  sweat-glands  aid  the  rest  of  the  body  ?     How  does  the  gall-bladder 
aid  the  small  intestine  in  digesting?     In  what  way  are  the  above  ac- 
tions performed?     What  do  these  few  examples  show? 

3.  In  thinking  of  communication   between  the  organs,  what  idea 


I92         DIAGRAM  OF   THE  NERVOUS  SYSTEM. 


FIG.  51.— Diagram  illustrating  the  general  arrangement  of  the  nervous  systeir. 


THE   CHIEF  NERVE-CENTRES.  1 93 

there  might  be  some  sort  of  telegraph-system  in  the 
body.  If  there  were  something  like  telegraph-wires 
running  from  all  the  organs  to  a  central  office  or  ex- 
change, then  word  of  the  state  and  needs  of  any  organ 
might  be  sent  from  it  to  the  central  office,  and  proper 
messages  be  sent  out  from  the  central  office  to  those 
other  organs  whose  help  was  wanted.  This  is  in  fact 
something  very  like  what  does  take  place. 

If  the  dead  body  be  dissected,  a  great  many  white 
cords  are  found  which  run  all  through  it,  and  go  into 
the  skin,  and  the  mucous  membranes,  and  the  heart,  and 
the  lungs,  and^each  muscle,  and  so  forth.  These  cords  are 
nerves.  If  one  be  followed  back  from  where  it  enters  any 
of  the  above  parts,  it  will  be  found  at  last  to  join  a 
much  larger  mass  to  which  other  nerves  are  also  united. 
This  mass  is  a  nerve-centre.  The  nerves  and  nerve- 
centres  together  make  the  nervous  system.  The  nerves 
answer  to  the  telegraph-wires,  and  the  centres  to  the 
main  offices  from  which  the  wires  spread  over  the 
country. 

4.  The  Chief  Nerve-Centres  are  the  brain,  the  spinal 
cord,  and  the  sympathetic  ganglia.  You  have  already  learned 
that  the  brain  lies  inside  the  skull  (p.  19),  and  the  spinal 
cord  runs  down  inside  the  back-bone.  At  the  under 
part  of  the  skull,  where  it  fits  on  the  back-bone,  is  a 
large  hole,  through  which  the  brain  and  spinal  cord 
unite.  Strictly  speaking,  therefore,  the  brain  and  spinal 
cord  make  only  one  centre;  they  are  often  spoken  of 

might  occur  to  us  ?  What  really  does  take  place  ?  What  are  nerves  ? 
What  is  found  when  a  nerve  is  traced  back  from  a  muscle  or  the  skin  ? 
Name  of  the  mass?  Of  what  does  the  nervous  system  consist?  To 
what  are  nerves  and  nerve-centres  compared  ? 

4.  What  are  the  chief  nerve-centres?  Where  does  each  lie?  HOW 
do  they  join  ?  What  is  the  cerebro-spinal  centre  ? 


194  THE  BRAIN. 

together  as  the  cerebro-spinal  centre.  The  sympathetic 
ganglia  will  be  described  farther  on. 

5,  The  Brain  of  an  adult  usually  weighs  about  three 
pounds. 

It  has  two  chief  parts  (Fig.  52),  the  great  brain  or  cere- 
brum, A,  and  the  small  brain  or  cerebellum,  B.  It  is  joined 
to  the  spinal  cord  by  the  medulla  oblongata,  D,  The  parts 


FIG.  52. — Diagram  illustrating  the  general  relationships  of  the  parts  of  the  brain 
as  seen  from  the  side.  A,  cerebrum  ;  £,  cerebellum  ;  Z>,  medulla  oblongata. 

of  the  brain  are  not  really  so  widely  separated  as  is  rep- 
resented, for  the  sake  of  clearness,  in  Fig.  52.  They  lie 
closely  packed  together,  as  shown  in  Fig.  53. 

The  cerebrum  fills  all  the  front  and  upper  part  of  the 
skull-cavity.  It  is  much  larger  than  the  cerebellum,  and 

5.  What  does  the  brain  of  a  grown  person  usually  weigh  ?  What 
are  its  chief  parts ?  How  joined  to  the  spinal  cord?  How  do  they 
lie  in  the  skull  ?  Relative  size  ?  What  are  the  cerebral  hemispheres? 
How  are  their  surfaces  marked  ?  Name  of  the  ridges  ? 


THE   SPINAL    CORD.— THE  NERVES.  19$ 

its  hinder  end  laps  over  it.  A  deep  groove  runs  along  the 
cerebrum  from  front  to  back  and  nearly  cuts  it  in  two. 
Its  halves  are  named  the  right  and  left  cerebral  hemi- 
spheres, and  their  surfaces  are  not  smooth  but  are  marked 
by  numerous  crooked  furrows,  with  ridges  between  (Fig. 
53).  The  ridges  are  known  as  the  convolutions. 


CIA 


FIG.  53.— The  brain   from  the  left  side.    Cb,  the  cerebrum,  or,  rather,  the  left 
cerebral  hemisphere;  Cbl^  the  cerebellum;  Mo,  the  medulla  oblongata. 

6.  The  Spinal  Cord  is  nearly  round,  and  is  about  three 
quarters  of  an  inch  across  and  seventeen  inches  long. 
It  does  not  reach  as  far  as  the  lower  end  of  the  back-bone. 

7.  The  Nerves  start  from  the  brain  and  spinal  cord. 
Twelve  pairs  (cranial  nerves]  are  attached  to  the  brain  and 
go  out  through  holes  in  the  skull;  thirty-one  pairs  (spinal 
nerves)  spring  from  the  sides  of  the  spinal  cord,  and  pass 
out  between  the  vertebrae. 

6.  Describe  the  spinal  cord.     How  far  does  it  reach  ? 

7.  Whence  do  the  nerves  start  ?    What  is  said  of  the  cranial  nerves  ? 
Of  the   spinal?    Of   the   nerve-fibres?     Describe   the   branching  of 
nerves, 


196 


SENSORY  AND   MOTOR  NERVES. 


Each  nerve  is  made  up 
of  a  number  of  very  slen 
der  threads,  named  ner&e- 
fibres,  which  run  side  by 
side  in  it  like  the  threads 
in  a  skein  .of  silk.  As  a 
nerve  is  followed  along 
from  its  centre,  it  is  found 
that  it  separates  into  small- 
er bundles  of  fibres,  which 
run  off  as  branches.  These 
branches  again  divide,  and 
so  on,  until  the  last  branches 
are  very  small  and  very 
numerous. 

8.  Sensory  and  Motor 
Nerve-Fibres. — A  telegraph- 
wire  is  used  to  send  mes- 
sages both  ways.  The  same 
wire  will  carry  a  message 
just  as  readily  from  New 
York  to  Chicago  as  from 
Chicago  to  New  York.  Our 
nerve-fibres  are  not  used 
in  this  way.  Some  of  them 
are  always  employed  to  car- 
ry messages  to  the  centres, 
others  to  carry  messages 
from  the  centres.  The  fibres 

8.  Point  out  an  important  differ- 
ence between  the  carrying  of  mes- 
sages by  telegraph-wires  and  by 
nerve-fibres.  What  is  meant  by 
sensory  fibres  ?  By  motor  ? 


REFLEX  MOVEMENTS.  197 

which  carry  towards  a  centre  are  usually  called  sensory 
fibres,  because  when  they  work  they  very  often  cause 
some  sensation  or  feeling.  The  fibres  which  carry  from 
a  centre  are  named  motor  fibres,  because  they  usually 
cause  some  muscle  to  contract,  and  thus  produce  move- 
ment. The  first  set  of  nerves  is  also  sometimes  called 
afferent  (from  a  Latin  word  meaning  bringing  to),  and 
the  other  set  efferent  (from  a  Latin  word  meaning  to 
bring  from).  These  names  are  better  than  sensory  and 
motor,  because  many  nerves  carry  messages  to  centres 
without  our  having  any  sensation  of  them,  and  many 
nerves  carry  messages  from  centres  to  other  organs  than 
muscles,  for  example  to  glands. 

9.  Reflex  Movements. — As  we  have  seen,  a  great  deal 
of  the  orderly  working  of  our  organs  is  brought  about 
without  our  will,  or  even  without  our  knowing  about  it. 
When  a  message  comes  to  a  nerve-centre,  the  centre  does 
not  merely  send  out  random  messages  along  any  outgo- 
ing nerve-fibres,  but,  as  it  were,  first  selects  the  organs 
to  be  set  at  work,  and  then  sends  the  proper  messages. 
As,  for  instance,  in  the  case  of  sneezing.  If  the  centre, 
warned  by  the  sensory  nerves  of  the  nose,  should  set  at 
work  any  or  every  outgoing  fibre  joined  to  it,  the  result 
would  not  be  a  sneeze,  but  some  sort  of  a  shaking-up  or 
convulsion  of  the  whole  body.  It  might  once  in  a  thou- 
sand times  be  useful,  but  in  most  cases  would  do  more 
harm  than  good.  The  disease  known  as  "  convulsions" 
is  due  to  the  fact  that  the  nerve-centres,  whenever  a 
nerve-fibre  brings  a  message  to  them,  send  out  random 

9.  How  is  the  involuntary  working  of  our  organs  managed  by  the 
nerve-centres  ?  Illustrate  from  the  case  of  sneezing.  What  happens 
if  the  nerve  centres  send  out  messages  to  the  wrong  organs?  To 


19$  REFLEX  MOVEMENTS. 

messages  to  all  the  muscles  instead  of  only  to  those 
whose  contraction  would  be  useful. 

Nerves  merely  carry  messages  to  and  fro.  Nerve- 
centres  do  much  more  than  this;  they  guide  the  mes- 
sages to  the  various  organs,  and,  in  all  ordinary  circum- 
stances, make  them  work  for  the  general  welfare  of  the 
body.  Most  nerve-centres  do  this  independently  of  our 
will;  they  set  the  proper  muscles  at  work  whether  we 
like  it  or  not,  though  the  cerebrum,  which  is  the  largest 
nerve-centre  and  only  one  where  the  will  acts,  sends 
out  most  of  its  messages  in  answer  to  the  will.  When 
food  goes  the  wrong  way  and  gets  into  your  larynx 
(p.  in)  you  cannot  help  coughing;  when  something 
comes  rapidly  close  up  to  your  eye  you  cannot  help 
winking;  when  you  chew  food  you  cannot  prevent  your 
salivary  glands  (p.  109)  from  pouring  out  extra  secretion. 
All  such  useful  movements,  guided  by  nerve-centres,  and 
not  dependent  on  our  will,  are  known  as  re  flex  movements. 
Sometimes  we  notice  them,  though  we  cannot  hinder 
them,  but  far  oftener  we  know  nothing  about  them. 
These  unconscious  reflex  movements,  guided  by  the 
nerve-centres,  carry  on  nearly  all  the  regular  daily  work 
of  the  body  necessary  to  keep  it  alive.  They  regulate 
the  circulation  and  the  breathing,  and  the  secretion  of 
the  digestive  liquids,  and  so  on.  The  medulla  oblongata 
especially  regulates  the  beat  of  the  heart  and  the  breath- 
ing movements;  if  it  is  seriously  injured,  death  occurs 
very  quickly. 

If  we  had  to  think  about  and   will  every  beat  of  the 

what  are  "  convulsions"  due?  What  is  the  function  of  nerves?  Of 
nerve-centres  ?  How  do  most  nerve-centres  behave  as  regards  our 
Will?  Illustrate.  Explain  what  is  meant  by  reflex  movements.  What 
is  said  of  our  consciousness  of  them  ?  Of  their  use  ? 


FEELING  AND   WILLING.  1 99 

heart,  and  the  drawing  of  every  breath,  and  the  secre- 
tion of  digestive  fluids  in  the  proper  amount  at  the 
proper  moment,  and  the  blood-flow  through  each  organ 
according  to  its  needs  at  that  time,  and  so  forth,  our 
minds  would  have  time  for  nothing  else.  All  this  daily 
routine  is  looked  after  by  nerve-centres  which  act  in- 
voluntarily, and  leave  the  mind  free  for  other  duties. 

10.  Feeling  and  Willing.— The  spinal  cord,  the  medulla 
oblongata,  and  the  cerebellum  direct  unconscious  and 
involuntary  movements.  The  cerebrum  guides  some 
such  movements,  but  it  does  more:  it  is  connected  in 
some  way  with  feeling  and  willing.  No  part  of  the  body 
which  is  not  joined  by  at  least  one  nerve-fibre  to  the 
cerebrum,  has  feeling  ;  and  no  muscle  not  joined  to  it  in 
like  way,  can  be  controlled  by  the  will. 

For  example,  the  nerve-fibres  coming  from  the  leg  all 
unite,  above  the  hip,  into  three  or  four  large  cords,  which 
enter  the  spinal  cord  near  its  lower  end.  If  all  the 
nerves  be  cut  at  the  ankle,  the  foot  loses  feeling,  and  all 
the  muscles  in  it  are  paralyzed;  that  is  to  say,  cannot  be 
made  to  contract  by  their  owner  when  he  wishes.  If 
only  some  of  the  nerve-fibres  going  to  the  foot  be  cut, 
then  only  that  part  of  it  to  which  the  divided  fibres  went, 
loses  feeling  and  has  its  muscles  paralyzed.  If  all  the 
nerves  be  cut  at  the  knee,  instead  of  the  ankle,  then  both 
the  foot  and  the  lower  part  of  the  leg  become  insensible 
and  paralyzed.  If  they  be  divided  or  crushed  at  the  hip- 
joint,  then  the  thigh  also  is  put  in  the  same  condition. 

10.  What  centres  direct  most  involuntary  movements?  What  part 
of  the  body  is  especially  concerned  in  feeling  and  willing?  What  is 
said  of  muscles  and  other  parts  not  joined  to  the  cerebrum  by  a  nerve- 
fibre  ?  Illustrate  from  the  results  of  injuries  to  the  nerves  of  the  leg 
at  the  ankle.  The  knee.  The  hip.  What  results  when  the  spinal 


2OO  THE  SYMPATHETIC  NERVOUS  SYSTEM. 

If  the  nerves  of  the  leg  be  not  injured  at  all,  but  the 
spinal  cord  be  cut  or  seriously  diseased  above  the  place 
where  they  join  it,  the  leg  loses  all  feeling  and  has  its 
muscles  paralyzed  just  as  if  its  nerves  themselves  were 
cut.  The  reason  of  this  is  tha*  ,»ie  nerve-fibres  which 
run  up  the  spinal  cord  to  the  cerebrum  and  cause  feel- 
ing, and  those  which  run  down  from  the  cerebrum  to 
the  leg  and  make  its  muscles  obey  the  will,  have  been 
divided.  The  spinal  cord,  in  addition  to  being  a  centre 
itself  for  many  reflex  movements,  is  a  sort  of  nerve  :  it 
affords  a  path  for  many  nerve-fibres  which  run  between 
the  cerebrum  and  most  parts  of  the  body. 

11.  The  Sympathetic  Nervous  System. — In  addition  to 
the  great  system  of  nerves  we  have  been  studying,  which 
branches  out  from  the  brain  and  spinal  cord,  and  then 
divides  and  divides  until  it  reaches  every  organ,  and 
covers  the  surface  of  the  body  as  closely  as  the  capilla- 
ries (p.  147)  do,  so  that  the  prick  of  a  pin-point  must 
touch  one  of  the  little  branches — in  addition  to  this  great 
set  of  cerebro- spinal  nerves  there  is  another,  called  the 
sympathetic  system.  The  nerves  of  the  sympathetic  system 
are  not  spread  through  the  skin  or  concerned  in  the 
sense  of  touch;  nor  are  they  subject  to  the  will  and  con- 
cerned in  producing  voluntary  movements.  But  they 
go  to  the  lungs,  and  the  heart,  and  the  liver,  and  the 
stomach  and  intestines,  and  to  the  involuntary  muscles 
(p.  42).  They  do  not  run  direct  to  the  brain  and  spinal 
cord,  but  first  to  certain  smaller  centres,  lying  principally 

cord  is  cut  above  where  the  nerves  of  the  leg  enter  it  ?  Why  ?  •  What 
is  the  spinal  cord  in  addition  to  being  a  centre? 

ii.  What  is  said  of  the  nerves  connected  with  brain  and  spinal 
cord  ?  Of  the  nerves  of  the  sympathetic  system  ?  What  is  a  gangli- 
on ?  Why  so  named  ?  What  is  the  sympathetic  system  ?  Its  duties  ? 


MIND  AND  BRAIN.  2OI 

in  two  rows  in  front  of  the  spinal  column  (s,  Fig.  i). 
Each  of  these  small  centres  is  named  a  gang/urn,  which  is 
the  Greek  word  for  a  swelling.  This  name  has  been 
given  them  because  they  make  swellings  on  nerves  like 
knots  on  a  string.  These  ganglia  are  joined  to  one  an- 
other and  to  the  brain  and  spinal  cord  by  nerves.  They, 
with  the  nerves  running  to  and  from  them,  look  after  a 
good  many  of  the  details  of  the  working  of  the  body. 
The  sympathetic  system  is  a  sort  of  tinder-servant  of  the 
brain  and  spinal  cord,  trusted  to  look  after  certain  routine 
work,  especially  the  distribution  of  the  blood  among  the 
various  organs,  according  as  their  needs  may  be.  It  has 
also  much  to  do  with  managing  the  glands.  It  owes 
its  name  to  the  fact  that  it  makes  many  organs  which 
are  not  under  direct  control  from  the  will,  work  together 
as  if  they  sympathized  with  one  another. 

12.  Mind  and  Brain. — The  cerebrum  is  not  only  con- 
cerned in  feeling  and  willing,  but  in  remembering  and 
reasoning,  and  in  all  the  other  things  which  go  to  make 
up  what  we  call  mind  and  character.  How  mind  is  con- 
nected with  brain  it  is  not  possible  to  imagine  ;  we  have 
just  to  accept  the  fact  that  it  is,  and  especially  with  its  fur- 
rowed and  ridged  surface.  When  this  is  seriously  dis- 
eased, feeling  is  lost  or  unnatural,  the  will  is  enfeebled, 
memory  weakened,  reason  impaired,  and  the  man  no 
longer  capable  of  judging  correctly,  nor  really  responsible 
for  his  actions.  Why,  or  how,  we  do  not  know,  and 


12.  With  what  besides  feeling  and  willing  is  the  cerebrum  con- 
cerned ?  What  is  said  of  the  connection  of  cerebrum  and  mind  ? 
What  part  of  the  cerebrum  has  especially  to  do  with  mind?  What  is 
seen  when  it  is  seriously  diseased  ?  What  is  it  sufficient  to  know 
concerning  the  connection  of  brain  and  mind,  for  all  practical  pur- 
poses ? 


202  MIND  AND  BRAIN. 

probably  never  will  know.  However,  for  all  practical 
purposes,  it  is  sufficient  to  know  that,  if  we  desire  active 
and  vigorous  minds,  we  must  try  to  keep  healthy  brains; 
we  may  then  consider  all  the  knowledge  we  can  get 
about  the  hygiene  of  the  brain  as  coming,  in  the  long- 
run,  to  the  same  thing  as  hygiene  of  the  mind. 


CHAPTER  XIX. 
HYGIENE  OF  THE   NERVOUS  SYSTEM. 

1.  Introductory. — The  nervous  system  is  so  closely 
connected  with  all  other  parts  of  the  body  that  any- 
thing which  injures  them  can  hardly  fail  to  hurt  it.  He 
who  desires  an  active  healthy  nervous  system  and  a 
vigorous  cheerful  mind,  must  strive  to  keep  muscles  and 
digestive,  circulatory,  and  respiratory  organs  in  health. 

On  the  other  hand  it  should  be  borne  in  mind,  that 
nearly  every  function  of  the  body  is  dependent  on  the 
nervous  system  for  its  proper  performance.  It  sets  at 
work  the  muscles  which  move  the  jaws,  and  the  glands 
which  secrete  saliva;  controls  the  oesophagus  in  swallow- 
ing; excites  the  glands  of  the  stomach,  and  makes  its 
muscular  coat  mix  the  gastric  juice  with  the  food;  it 
governs  the  secretion  of  pancreatic  juice  and  bile,  which 
turn  the  chyme  into  chyle;  makes  the  muscular  coat  of 
the  intestine  drive  the  digesting  mass  along  that  tube, 
and  controls  absorption  by  its  lacteals  and  blood-vessels; 
it  regulates  the  beat  of  the  heart,  and  the  diameter  of 
the  arteries,  and,  thus,  the  blood-flow  to  every  organ;  it 

i.  What  is  said  of  the  connection  of  the  nervous  system  with 
other  parts  of  the  body  ?  What  must  one  do  who  desires  an  active 
nervous  system  and  mind?  What  should  also  be  borne  in  mind? 
Give  illustrations  of  the  action  of  the  nervous  system  in  preparing 
food  to  enter  the  stomach.  In  controlling  its  digestion  in  the  stom- 
ach. On  conversion  of  chyme  into  chyle?  On  the  movements  of 
the  intestine?  On  absorption?  On  the  blood-flow?  On  excretion? 


204  SOME  NERVOUS  DISEASES. 

keeps  in  action  the  lungs,  and  skin,  and  kidneys  to 
purify  the  blood;  it  makes  the  eye  see  and  the  ear  hear; 
and  through  it  we  think,  and  hope,  and  love.  To  injure 
the  nervous  system  by  too  much  work,  too  little  sleep, 
or  over-indulgence  in  tobacco,  alcohol,  or  any  other  sub- 
stance which  affects  it,  is  to  weaken  every  function  of 
the  body  and  the  mind. 

No  doubt  many  persons  have  attained  intellectual 
eminence  and  led  happy  and  useful  lives  in  spite  of 
bodily  feebleness.  Unusual  strength  of  will  has  enabled 
them  to  overcome  the  odds  against  them.  But  we 
should  remember  that  body  and  mind  are  so  united 
that  any  disease  of  one  affects  the  other,  and  she  aid 
guide  our  conduct  accordingly. 

2.  Some  Disorders  of  the  Nervous  .System. — Unhappily 
most  children  have  seen  cases  of  "  St.  Vitus'  Dance"  It 
is  a  twitching  of  the  muscles,  sometimes  only  those  of 
the  face,  sometimes  those  of  the  limbs  and  body  gener- 
ally. It  comes  from  weakening  of  the  control  of  the 
nervous  system  over  the  muscles,  so  that  occasionally 
some  muscle  relaxes.  This  enables  the  opposing  muscle 
to  give  a  jerk  and  pull  the  organ,  it  may  be  the  eyelid, 
the  mouth,  the  arm,  or  the  leg,  out  of  place.  Sometimes 
these  jerkings  are  so  violent  as  to  seriously  injure  the 
organs. 

Fit  is  a  name  given  to  several  disorders  attended  with 
loss  of  consciousness.  A  fainting  fit  is  due  to  temporary 
weakness  of  the  heart;  it  pumps  so  little  blood  around 
that  the  cerebrum  does  not  get  enough  nourishment  to 

What  are  the  consequences  of  injuring  the  nervous  system  ?    What 
have   some   persons   of  feeble   body   accomplished  ?     How  ?     What 
should  we  remember  ? 
2.  What  is  St.  Vims'  dance  ?    To  what  due  ?    To  what  is  a  fainting 


FAINTING— HYSTERICS.  2O$ 

enable  it  to  work.  A  person  who  has  fainted  should  be 
laid  at  once  flat  on  the  back,  with  the  head  low;  this 
enables  blood  to  be  pumped  more  easily  to  the  brain. 
The  skin  may  then  be  stimulated  by  sprinkling  the  face 
briskly  with  cold  water,  or  the  nose  by  holding  harts- 
horn to  the  nostrils.  The  convulsions  so  common  among 
infants  are  in  most  cases  excited  by  some  irritation  con- 
nected with  the  alimentary  canal.  An  emetic  should  be 
given  at  once,  cold  applied  to  the  head,  and  the  body 
put  in  a  warm  bath.  In  epileptic  fits  there  is  usually  a 
peculiar  cry,  the  face  becomes  pale,  consciousness  is 
lost,  and  then  convulsions  (p.  197)  occur.  Lay  the  per- 
son flat,  and  restrain  any  of  his  movements  likely  to  in- 
jure him.  If  possible,  a  folded  handkerchief  should  be 
pushed  between  the  teeth  to  prevent  biting  of  the 
tongue.  After  the  convulsions  have  ceased,  quiet  is  de- 
sirable. Hysterical  fits  assume  many  different  forms,  the 
more  frequent  perhaps  being  unreasonable  screaming, 
laughing,  and  weeping  by  turns.  They  should  be 
noticed  as  little  as  possible.  A  display  of  interest  and 
sympathy  nearly  always  makes  a  fit  of  hysterics  last 
longer.  A  little  rudeness,  exciting  anger,  is  often  the 
best  treatment. 

An  apoplectic  fit  or  apoplexy  is  due  to  the  bursting  of 
some  blood-vessel  of  the  brain.  The  blood  which  flows 
out  compresses  the  brain,  and  the  person  becomes  more 
or  less  unconscious.  The  breathing  is  heavy  and  like 
snoring,  and  the  face  usually  flushed.  A  person  suffer- 
ing from  an  apoplectic  fit  should  not  be  moved  at  all  if 

fit  due?  Treatment.  What  is  said  of  the  convulsions  of  young  chil- 
dren ?  Characters  of  an  epileptic  fit  ?  What  is  said  of  hysterical  fits  ? 
Cause  of  an  apoplectic  fit  ?  Symptoms  ?  What  is  said  of  the  manage- 
ment of  a  person  in  an  apoplectic  fit?  What  is  neuralgia?  On  what 


206  NEURALGIA. 

it  can  be  avoided;  apply  cold  to  the  head  until  medical 
aid  can  be  obtained. 

Neuralgia  is  a  diseased  condition  attended  with  in- 
tense pain,  which  may  attack  almost  any  part  of  the 
body.  It  seems  to  depend  on  an  altered  or  disordered 
state  of  the  nerves  themselves,  for  usually  nothing  can 
be  found  wrong  in  the  organ  in  which  the  pain  is  felt. 
Thus  the  teeth  or  the  stomach  may  appear  to  be  perfect- 
ly sound  in  their  structure,  and  yet  suffer  intensely  from 
neuralgia.  The  almost  unbearable  pain  often  leads  to 
the  use  of  alcohol,  opium,  and  chloral  (Chap.  XX.),  drugs 
which,  while  giving  temporary  relief,  tend  to  increase 
the  diseased  condition  of  the  nerves.  Some  persons 
have  organizations  more  nervous  than  those  of  others, 
and  under  unfavorable  conditions  of  life  are  very  apt 
to  become  victims  of  neuralgia.  These  persons  may 
be  recognized  by  their  tendency  to  undertake  more 
than  they  have  the  strength  to  perform  safely,  and  to 
be  extreme  in  all  their  feelings.  They  should  guard 
against  lives  of  excitement,  and  be  careful  to  secure 
plenty  of  sleep,  and  not  to  allow  themselves  to  be  over- 
driven by  ambition. 

3.  The  Three  Great  Sources  of  Nervons  Health  are  a 
brave  heart,  a  cheerful  disposition,  and  plenty  of  sleep. 

Nothing  wears  the  nerves  like  worry.  The  child  at 
school  who  keeps  a  brave  heart  for  whatever  may  hap- 
pen stands  a  better  chance  of  success  than  the  one  who 
wears  his  nerves  out  with  constant  dread  of  failure.  One 

does  it  depend  ?  Illustrate.  To  what  does  it  often  lead  ?  How 
may  persons  apt  to  become  neuralgic  be  recognized  ?  What  precau- 
tions should  they  take  ? 

3.  What  are  the  three  great  sources  of  nervous  health  ?  What  is 
said  of  worry  ?  Of  the  effect  of  a  brave  heart  in  promoting  success  ? 
Of  the  benefits  of  a  cheerful  disposition  ? 


SLEEP.  207 

who  has  a  cheerful  disposition  and  a  sunny  temper  is  not 
only  unlikely  himself  to  suffer  from  nervous  ailments, 
but,  by  a  contagious  influence,  helps  to  keep  others  well 
and  happy. 

4.  Sleep,  however,  sound  and   plenty  of  it,  is   the  one 
great  condition  of  nervous  health.     The  use  of  sleep  is  to 
give  the  cerebrum  a  period  of  complete  rest,  for  growth 
and  repair.     While  awake,  even  when  we  are  not  doing 
brain-work,  the  mind  and  cerebrum  are  in  action  all  the 
time;    feeling  and  willing  and   thinking.     Perhaps    not 
feeling  much  or  willing  much  or  thinking  hard,  but  still 
doing  some  or  all  of  those  things  every  moment.     So  long 
as  we  are  conscious,  the  mind  and  cerebrum  are  at  work. 
Healthy  sound  sleep  is  a  state  of  the  body  in  which  the 
cerebrum  is  entirely  at  rest  and  there  is  no  conscious- 
ness.    A  due  amount  of  it  is  as  absolutely  necessary  for 
a  healthy  brain  and  mind,  as  periods  of  rest  are  for  the 
muscles  or  stomach. 

5.  The  Amount  of  Sleep  Necessary  for  Health    varies 
with  age  and  employment.     Children  need  more  sleep 
than  older  persons,  and  those  whose  chief  work  is  men- 
tal, need  more  than  those  whose  work  is  muscular. 

The  brain  of  a  child  has  to  grow  and  develop  and  is 
easily  fatigued;  it  needs  plenty  of  the  deep  thorough 
rest  given  by  sleep.  Moreover  the  muscles  of  a  healthy 
boy  or  girl  are  full  of  life,  and  need  abundant  exercise. 
This  makes  severe  mental  work  dangerous  (p.  57).  The 
organs  which  nourish  the  body,  can  only  in  a  few 
favored  persons  provide  at  the  same  time  for  the  needs 

4.  What  is  the  use  of  sleep  ?     What  is  said  concerning  mind  and 
cerebrum  during  waking  hours?     What  is  healthy  sound  sleep? 

5.  What  persons  need  most  sleep  ?    First  reason  why  children  need 
more  than  adults?    Another  reason?    What  is  fhe  usual  result  of 


208  MENTAL   EXERCISE. 

of  active  growing  muscles  and  hard-worked  nervt>us 
systems.  The  attempt  to  make  them  do  so,  is  very  apt 
to  stunt  and  injure  both.  As  we  grow  older,  and  the 
demands  of  the  body  for  extra  materials  for  its  growth 
become  less  or  cease,  more  steady  and  continued  brain- 
work  can  be  undertaken  with  safety  and  benefit. 

The  "  soundness"  of  the  sleep  is  important.  Five  or 
six  hours  of  thorough  deep  sleep,  with  no  dreams  or 
consciousness  of  any  kind,  are  better  than  eight  or  nine 
hours  of  uneasy  sleep.  Sleepnessness  (insomnia)  is  a 
very  serious  matter;  if  continued  or  frequent,  medical 
advice  should  be  obtained.  Unless  checked,  it  leads  to 
exhaustion  of  the  brain,  and  impairment  of  the  mind. 

6.  The  Brain  Needs  Exercise. — If  the  body  in  general 
is  healthy,  the  involuntary  nerve-centres  will  look  after 
their  own  work,  and  take  proper  exercise  and  rest ;  but 
the  part  of  the  brain  concerned  with  mental  work  is 
more  under  our  control,  and  may  be  harmed  by  over- 
work or  idleness.  It  is  made  stronger,  and  the  mind 
more  vigorous,  by  regular  exercise. 

When  one  first  begins  to  train  his  muscles  to  do  any 
special  task,  they  soon  tire,  but  after  a  time  the  work 
becomes  easy,  and  more  difficult  feats  can  be  under- 
taken. In  like  way,  mental  work  is  apt  at  first  to  be 
very  fatiguing,  but  regularly  repeated,  with  proper  in- 
tervals of  rest,  it  becomes  easier  every  time;  and  soon 
harder  tasks  can  be  accomplished,  and  even  enjoyed. 

trying  to  work  hard  with  both  brain  and  muscles  ?     What  is  said  of 
sound  sleep  as  compared  with  restless  ?     Of  sleeplessness? 

6.  What  do  the  involuntary  nerve-centres  do  in  health  ?  What 
part  of  the  nervous  system  is  more  in  our  control  ?  What  is  the 
effect  of  exercise  on  the  mind?  What  is  the  result  of  training  the 
muscles?  The  mind?  What  is  said  of  the  effects  of  idleness  on  the 
mind? 


MENTAL  EXERCISE.  209 

An  idle  mind,  like  idle  muscles,  becomes  weak.  Even 
if  it  remain  in  a  few  cases  shrewd  and  clear,  it  is  inca- 
pable of  prolonged  steady  effort,  such  as  may  any  day 
become  necessary.  There  are  mental  loungers  as  well 
as  muscular;  and  the  former  are  rather  the  more  con- 
temptible. 

7.  Mental  Exercise  should  be  Varied. — You  have  learned 
(p.  57)  that  a  man  may  exercise  and  greatly  develop 
some  of  his  muscles,  and  leave  others  idle  and  feeble. 
A  great  many  people  do  something  of  this  kind  with 
their  brains.  They  use  and  train  some  mental  faculties 
and  leave  the  rest  unemployed  until  they  almost  cease 
to  be  active  at  all.  The  hard  struggle  which  most  of 
us  have,  nowadays,  to  make  a  place  for  ourselves  in  the 
world  and  keep  it,  is  very  apt  to  lead  to  this  mental  lop- 
sidedness,  which  is  as  much  a  deformity  as  would  be 
huge  arms  and  spindling  legs  on  the  same  body.  We 
meet  business-men  so  absorbed  in  money-getting  that 
they  care  for  no  books  except  ledgers,  no  science  unless 
it  helps  them  to  patent  some  invention.  We  meet  men 
of  science  who  take  no  interest  in  art  or  literature,  or 
who  affect  to  despise  the  business-men  who  are  carry- 
ing on  the  great  commerce  which  promotes  the  progress 
of  the  world  in  ten  thousand  ways.  We  meet  literary 
men  who  seem  quite  incapable  of  sympathy  with  science, 
and  artists  who  care  for  nothing  outside  of  art.  All 
such  people  may  be  very  far  from  insane,  in  the  usual 
sense  of  the  word,  but  they  are  all  mentally  deformed. 

7.  How  do  some  people  train  their  mental  faculties?  What  often 
leads  to  mental  lopsidedness?  To  what  is  it  compared  ?  Give  illus- 
trations of  persons  who  use  only  a  small  part  of  their  mental  faculties. 
What  is  said  of  mental  deformity  ?  Why  is  a  broad  education  in 
early  life  very  valuable  ? 


210  BRAIN-REST. 

Some  are  born  so  and  cannot  help  it,  but  a  great  many 
have  made  themselves  so  by  persistently  neglecting  to 
use  many  of  their  intellectual  faculties. 

After  a  man  gets  settled  down  to  his  business,  what- 
ever it  be,  he  rarely  has  much  time  or  energy  to  devote 
to  other  things.  Hence  arises  the  value  of  a  broad  edu- 
cation in  early  life,  tending  to  widen  the  range  of  our 
sympathies  and  interests. 

8.  Education. — All    education   worthy  the    name,   not 
merely  supplies  instruction  in    certain  things  useful  to 
know,  but  trains  the  will  and  strengthens  the  character. 
For  this  reason  it  should  include  the  performance  of  un- 
pleasant or  difficult  duties.     Every  man  and  woman  has 
to  face  many  such  duties  in   the  course  of  life,  and    the 
will  must  be  made  strong  to  meet  them.     A  school  where 
every  study  is  made  easy  and  pleasant  may  be  popular, 
but  it  is  not  the  best  school  to  turn  out  real  men  and 
women,  strong  to  play  a  noble  part  in  life. 

9.  The  Brain  Needs  Rest  as  well  as  Work. — Overwork, 
giving    no   sufficient    periods  of  rest  for    repair   of    the 
nerve-substance   destroyed    during    activity,  harms   the 
brain  very  much  in  the  same  way  as  it  does  the  muscles 
(p.  52).     The   results  of  mental  overwork  are,  however, 
apt  to  be  far  more  disastrous   than  those  of  muscular. 
Muscles  which  have  been  exercised  too  much  usually  re- 
cover completely  with  rest  and  nourishment,  and  become 
as  strong  as  ever :  a   brain  which   has    given  way  under 
overwork,  is  very  apt  never  again  to  be  as  capable  of 

8.  What  does  all  good  education  do?    Why  should  it  include  diffi 
cult  tasks  ?     Why  must  the  will  be  made  strong? 

9.  What  is  said  of  overwork  of  the  brain  ?     Why  worse  than  of  the 
muscles?     What  are  the  mental   symptoms   of  an   overtaxed   brain? 
How  is  the  body  in  general  affected  by  it?     How  does  it  often  lead 
to  drunkenness  ? 


BRAIN-REST.  211 

continued  labor  as  it  would  have  remained,  had  it  been 
used  wisely. 

Apart  from  mental  symptoms,  as  sleeplessness,  con- 
fusion of  thought,  low  spirits,  loss  of  memory,  and  inca- 
pacity for  prolonged  steady  thought,  an  overtaxed  brain 
acts  on  the  whole  body  and  injures  it.  The  digestion 
especially  is  impaired,  and  this  of  course  brings  in  its 
train  many  evils,  due  to  ill-nourishment  of  various  organs 
(see  pp.  123-4).  The  feeling  of  lassitude  and  exhaustion 
causes  a  longing  for  stimulants,  which  give  temporary 
relief,  and  many  a  man  has  thus  become  a  drunkard. 

10.  Brain-Rest  Obtained  by  Change  of  Employment. — 
There  is  an  old  saying  that  "change  of  employment  is  as 
good  as  rest;"  properly  understood  it  is  a  very  true  one. 
The  change,  however,  must  be   thorough.     It  is   not  of 
much  use  for  a  business-man   to  go,  in  search  of  rest, 
from  New  York  to  Saratoga  and  there  continue  his  busi- 
ness by  correspondence;  nor  for  a  child   to  change  from 
studying  history  to  arithmetic.      Unless   the  change   is 
accompanied  by  a  sense  of  recreation  and  pleasure,  it  is 
of  little  or  no  value  as  affording  brain-rest.     Doing  noth- 
ing is  often  wearisome  to  persons  who  have  never  formed 
habits    of  idleness;  when    the    minds   of  such  need  rest, 
they  should  seek  some  occupation  calling  for  little  exer- 
cise of  the    faculties  employed    in    their   regular   daily 
work,  and  which  yet  interests  and  amuses  them. 

11.  Concentrating  One's  Thoughts. — One  of  the  hardest 
things  a  child  has  to  learn,  is  to  "  fix  its  attention,"  or 

10.  What   is   necessary  that  change  of  employment   may  rest  the 
mind?      Illustrate.      What  should  accompany  the  change?       What 
should  those  seek  who  soon  weary  of  doing  nothing  and  yet  need 
brain-rest? 

1 1 .  What  is  said  of  fixing  the  attention  ?     Illustrate.      How  may  the 
power  be  acquired  ?    Why  should  the  training  be  gradual  ? 


212    ACTION  OF  ALCOHOL   ON  NERVOUS  SYSTEM. 

keep  its  mind  from  being  distracted  and  wandering  off 
to  other  things.  A  great  many  grown  people,  indeed, 
cannot  do  it.  A  very  distinguished  American  lecturer, 
writer,  and  anatomist,*  has  stated  that  he  could  gauge 
the  intelligence  of  his  audience  by  the  way  in  which 
they  behaved  when  any  slight  disturbance  occurred 
during  his  lecture.  On  an  educated  audience,  with 
trained  power  of  attention,  any  slight  noise  had  little 
influence,  while  less  educated  hearers  turned  their  heads 
at  every  trivial  interruption. 

To  acquire  this  power  of  attention,  is  most  important. 
Probably  no  young  healthy  child  has  it;  it  must  be 
gained  by  prolonged  training,  but  the  training  should 
be  gradual.  A  young  child  cannot  fix  its  mind  on  a 
lesson,  no  matter  how  easy,  for  an  hour  at  a  time. 
Short  lessons,  with  frequent  brief  intervals  in  which  the 
attention  is  permitted  to  relax,  should  be  given  at  first. 

12.  The  Effects  of  Alcohol  on  the  Nervous  System  and 
their  Symptoms. — Alcohol  is  a  terribly  frequent  cause  of 
nervous  diseases.  In  over-stimulating  the  brain  and 
spinal  cord,  it  impairs  their  structure,  weakens  their 
functions,  and  often  leads  to  insanity  and  crime. 

A  small  quantity  of  wine  or  spirits,  taken  by  one  not 
accustomed  to  it,  congests  and  excites  the  brain;  the 
person  gets  restless  and  talkative,  then  dizzy  and  unable 
to  think  clearly.  He  is  soon  overcome  by  sleep,  and  on 
awaking  feels  out  of  sorts. 

If  the  dose  be  increased,  the  talkativeness  is  accompa- 

12.  What  is  the  action  of  alcohol  on  the  brain  and  spinal  cord  ? 
What  is  the  action  of  a  glass  of  wine  on  a  person  not  used  to  it  ? 

*  Professor  Oliver  Wendell   Holmes. 


NERVOUS  ALCOHOLIC  DISEASES.  21$ 

nied  by  indistinct  speech  and  the  dizziness  by  trembling 
hands  and  a  staggering  walk,  both  showing  loss  of  con- 
trol over  the  voluntary  muscles  and  the  will.  The  sense 
of  touch  is  dulled;  the  eyeballs  do  not  move  together,  so 
as  to  look  exactly  at  the  same  point  at  the  same  moment, 
and  objects,  accordingly,  appear  double.  (You  may  imi- 
tate this  effect  by  pushing  one  eyeball  gently  while 
looking  with  both  eyes  at  something.)  Then  follows 
profound  drunken  sleep,  which  may  pass  into  "  coma," 
a  condition  of  deep  unconsciousness  from  which  the 
person  cannot  be  aroused,  and  in  which  the  breathing  is 
slow  and  labored  because  the  involuntary  nerve-centres 
which  govern  the  breathing-muscles  are  affected.  Some- 
times these  centres  become  at  last  quite  paralyzed  and 
death  results,  but  more  often  the  man  sleeps  off  his 
drunken  fit,  to  awaken  with  a  state  of  his  nerves  to  be 
relieved  only  by  renewed  drinking,  followed  each  time 
by  worse  results. 

The  nerve-centres,  however,  soon  get  used  to  the 
stimulant;  it  takes  a  larger  amount  each  time  to  make 
them  unsteady,  but  all  the  while  brain  and  spinal  cord 
are  becoming  surely,  if  slowly,  diseased. 

13.  Some  of  the  Nervous  Diseases  due  to  Alcohol. — Deli- 
rium tremens  (trembling  madness)  is  a  frightful  form  of 
temporary  madness,  accompanied  by  great  trembling. 
The  senses  are  partly  lost;  the  man  sees  spectres,  usually 
foul  and  horrible,  about  him,  and  has  all  sorts  of  terrify- 
ing visions.  He  is  at  times  violently  excited  and  raving 

What  if  the  amount  be  increased?  What  is  coma?  Why  is  the 
breathing  labored  during  coma?  What  may  result?  Why  is  one  fit 
of  drinking  likely  to  lead  to  another?  Why  does  it  need  more  alcohol 
to  make  a  practised  toper  drunk  ? 

13.  What  is  delirium  tremens ?     Its  symptoms?     Its  causes?     Dip- 


214  NERVOUS  ALCOHOLIC  DISEASES. 

mad;  in  the  intervals,  utterly  prostrate,  sleepless,  and  a 
prey  to  indescribable  terrors  of  the  imagination. 

Repeated  drunkenness  usually  ends  in  an  attack  of 
this  disease,  but  it  is  more  frequently  the  result  of  con- 
tinued hard  drinking  in  persons  who  have  never  become 
actually  drunk.  It  is  especially  apt  to  occur  in  those 
who  drink  to  "keep  them  up"  while  engaged  in  hard 
mental  work. 

Dipsomania  is  a  diseased  condition,  often  only  showing 
itself  at  long  intervals,  and  marked  by  a  mad  passion 
for  alcohol.  However  disgusting  a  liquid  containing 
alcohol  may  be,  the  dipsomaniac  will  swallow  it  greedily. 
While  the  fit  is  on  him  he  is  as  irresponsible  as  a  mad- 
man, and  his  only  safety  is  in  being  restrained  as  one. 

This  disease  is  sometimes  produced  by  indulgence  in 
drink,  but  is  more  often  inherited  from  parents  who 
have  been  drunkards.  Sufferers  from  it  are  entitled 
to  sympathy  to  which  the  common  drunkard  has  no 
claim. 

Paralysis,  epilepsy,  and  insanity  often  result  from  drink- 
ing. There  is,  in  fact,  no  kind  of  madness  or  of  nervous 
disease  which  may  not  be,  and  has  not  been  over  and 
over  again,  produced  by  alcoholic  drinks.  Many  of 
these  diseases  have  other  causes  also,  but  none  so  fre- 
quent as  alcohol. 

Perhaps  the  greatest  evil  of  intemperance  is  that  the 
drunkard  so  often  transmits  to  his  innocent  children 
some  form  of  nervous  disease.  In  the  families  of  such 
are  found  the  weak  in  body,  weak  in  mind,  weak  in  will, 

somania?  Symptoms?  Treatment?  Cause?  Name  other  nervous 
diseases  produced  by  drinking.  What  is  said  of  the  causes  of  mad- 
ness and  nervous  diseases?  Of  the  transmission  of  such  diseases  to 
a  drunkard's  children  ?  What  do  we  find  in  the  families  of  drunkards  ? 


NERVOUS  ALCOHOLIC  DISEASES. 

weak  in  character:  the  epileptic,  the  rickety  child,  the 
half-witted,  the  idiot,  the  dipsomaniac,  the  maniac; 
children  who  grow  up  unable  to  honestly  make  their 
way  in  the  world,  and  become  public  burdens  in  insane 
asylums,  prisons,  or  poorhouses. 


CHAPTER  XX. 
NARCOTICS. 

1.  Narcotics. — Certain  drugs  have  the  power  of  making 
the  cerebrum  unable  to  work  for  a  time;  they  thus  cause 
unconsciousness,  and  produce  what  seems  to  be  sound 
sleep.     Substances  which  act  on  the  nervous  system  in 
this  way,  are  named  narcotics.     In  small  doses,  they  often 
relieve  pain   without  causing  actual  loss  of  conscious- 
ness.    Chloroform,  chloral,  ether,  opium,  laudanum,  and 
morphia  are  examples  of  narcotics.     Tobacco   may  be 
included,  since,  when  not  taken  as  a  mere  idle  luxury,  it 
is  employed   to  soothe   the  nerves.      Alcohol    in    large 
doses  is  also  a  narcotic.     Occasionally,  in  a  crisis  of  dis- 
ease, when  sleep  must  be  obtained  at  any  cost,  or  terrible 
parn  is  wearing  out  the  strength  of  the  sufferer,  a  nar- 
cotic, carefully  ordered  in  proper  dose  by  a  physician,  is 
a  very  valuable  medicine.     Taken  habitually,  narcotics 
weaken  the  mind,  injure  the  whole  nervous  system,  and 
cause  many  diseases. 

2.  Opium  and  Morphia. — Opium  is  a  gummy  mixture 
obtained  from  a  kind  of  poppy.     Its  chief  active  prin- 
ciple is  morphia.     The  forms  in  which  opiates  are  most 
used  are:  (i)  gum  opium,  the  natural  substance,  often  put 

1.  What  power  have  narcotics?     What  if    taken   in  small  dose? 
Give  examples  of  narcotics.     When  is  tobacco  one?     Alcohol? 

2.  What  is  opium?     Morphia?     What  are  the  commonest  forms  of 
opiates  ? 


OPIUM-EA  TING.  2 1 7 

up  in  the  form  of  pills;  (2)  laudanum,  made  by  dissolving 
opium  in  alcohol;  (3)  paregoric,  a  liquid  containing  sev- 
eral ingredients,  of  which  opium  is  the  most  important; 
(4)  morphia,  and  solutions  containing  it. 

3.  The    Opium   Habit. — Opium    is   perhaps   the    most 
valuable  drug  at  the  disposal  of  the  physician.     On  the 
other  hand,  it  is  one  of  the  most  hurtful  substances  used 
by  mankind.     It  may  be  that  it  does   not  do  as  much 
harm  in  the  United  States  as  alcoholic  drinks,  but  only 
because  not  so  many  persons  have  taught  themselves  to 
crave  it.     Used  constantly,  it  is  as  surely  fatal,  and  the 
habit  is  perhaps  even  harder  to  break,  for  it  may  be  in- 
dulged more  secretly,  and  its  effects  are  not  so  readily 
recognized.     There  is    this,   also,   to   be   said:    most  of 
those  who  kill  themselves  by  drink  are  persons  of  weak 
will,  while  many  a  one  of  highest  gifts  and  nobles,t  char- 
acter, who  would  loathe  the  low  vice  of  drunkenness,  has, 
before  knowing  the  danger,  become  the  hopeless  victim 
of  opium.      Using  the  drug,  at  first,  as   ordered   by  a 
physician   for  the   relief  of  pain,  he  (or-  she,   for  more 
women  than  men  are  given  to  opium-excess)  is  scarcely 
conscious  of  danger,  until  the  repeated  employment  of 
the  drug  has  created  an  almost  irresistible  craving  for  its 
continuance.     Most   medical   men    now  fully  recognize 
the  danger,  and  only  order  prolonged  use  of  opium  with 
great  caution. 

4.  The  Diseased  Conditions  Produced  by  Regular   Use 
of  Opium. — The  first  effect  is  deadening  of  sensibility, 
accompanied  by  mental  exaltation,  if  the  dose  be  small. 

3.  What  is  said  of  opium  ?     Of  its  harmfulness  as  compared  with 
alcohol  ?     Why  is  opium  more  disastrous  from  one  point  of  view  ? 
How  is  it  now  given  by  physicians? 

4.  What  are  the  first  effects  of  a  dose  of  opium?    What  is  the  con- 


2l8  EFFECTS  OF  OPIUM  ON  HEALTH. 

This  is  succeeded  by  unnatural  sleep,  disturbed  by  fan- 
tastic dreams. 

On  awaking,  there  is  great  depression  of  mind  and 
body:  often  associated  with  defective  memory,  and  a 
feeling  that  something  terrible  is  about  to  happen. 
There  is  muscular  weakness;  distaste  for  food,  without 
actual  nausea;  and  an  almost  irresistible  craving  for  an- 
other dose. 

If  the  habit  be  continued  further,  mental  and  physical 
changes  occur.  Distaste  and  inaptitude  for  any  kind  of 
exertion;  weakened  digestion;  not  enough  secretion  of 
bile;  slow  action  of  the  muscles  of  the  bowels,  causing 
constipation.  The  voluntary  muscles  waste,  the  skin 
shrivels,  and  the  person  gets  the  appearance  of  old  age 
prematurely.  The  pulse  is  quick,  the  body  feverish; 
the  eye  dull,  except  just  after  taking  a  dose  of  the  drug. 

Next  comes  failure  of  the  nervous  system.  The  legs 
are  partly  paralyzed,  and  then  the  muscles  of  the  back. 
The  victim  crawls  along,  bent  like  an  old  man.  Death 
finally  results  from  starvation,  due  to  complete  failure  in 
the  working  of  the  digestive  organs. 

5.  Morphia  or  Morphine. —  When  morphia  is  used,  a 
solution  of  it  is  usually  injected  under  the  skin  by  a 
sharp-pointed  syringe.  Continued  use  of  it  in  this  or  any 
other  way  is  followed  by  all  the  symptoms  of  opium- 
poisoning  above  described,  and  has  the  same  fatal  ending. 
The  digestive  organs  are  not  so  quickly  injured;  but,  on 
the  other  hand,  the  repeated  punctures  of  the  skin  cause 
inflammation  and  sores. 

dition  of  the  person  on  awaking  ?  What  results  follow  continuance 
of  the  habit  ?  How  does  opium  affect  the  nervous  system  ? 

5.  How  is  morphia  usually  given  ?  Results  of  its  continued  use? 
Compare  its  effects  with  those  of  opium. 


CHLORAL.  219 

6.  Banger    of   Administering    Opiates    to    Children.  — 

Children  are  extremely  easily  poisoned  by  opium  and  all 
things  containing  it  or  morphia.  They  should  never  be 
given  to  a  child  except  on  the  order  of  a  physician,  and  exactly 
as  ordered.  Many  an  infant  has  been  killed  by  paregoric 
or  some  "  soothing  syrup"  containing  opium,  given,  with- 
out medical  advice,  by  a  parent  or  nurse  to  stop  diar- 
rhoea or  produce  sleep. 

7.  Chloral,  Chloral  Hydrate,  Syrup  of  Chloral. — A  few 
years  ago,  chloral  was  proclaimed  a  wonderfully  harm- 
less  narcotic:    it  caused  sleep  or  lessened  pain  without 
harm,  it  was  said,  to  mind  or  body.  •  Physicians  have 
since  learned  that  it  is  not  at  all  the  harmless  drug  they 
formerly  believed  it,  but  many  other  people  have  not  yet 
had  their  eyes  opened  to  its  dangerous  character.     Vari- 
ous preparations  containing  it  are  sold  in  drugstores  to 
any  one  asking  for  them;  and  many  persons  who  would 
hesitate   to   take    opiates   without    medical   advice,   use 
chloral,  believing  it  quite  safe  and  harmless. 

Chloral,  taken  habitually,  is  at  least  as  mischievous  as 
opium.  To  retail  it  in  any  form  except  on  the  prescrip- 
tion of  a  physician,  should  be  made  illegal. 

The  chloral  habit  is  acquired  with  great  ease,  and  is 
very  hard  to  break.  The  first  phenomena  of  chloral  dis- 
ease (chloralisni)  are  these:  The  digestion  is  greatly  im- 
paired; the  tongue  is  dry  and  furred;  there  is  nausea; 
sometimes  vomiting,  and  a  constant  feeling  of  oppres- 
sion from  wind  on  the  stomach. 


6.  Why  should  opiates  never  be  given  to  a  child  except  by  a  physi- 
cian's order?     What  has  resulted  from  neglect  of  this  precaution? 

7.  What  was  believed  of   chloral   a   few   years   ago  ?     What  have 
medical  men  lately  learned  about  it?     Why  do  so  many  people  take 
chloral   without   medical   advice  ?     Describe   the   first   symptoms   of 


220  BROMIDES. 

Next,  nervous  and  circulatory  disturbances  occur. 
The  temper  becomes  irritable,  the  will  weak;  the  hands 
and  legs  tremulous;  the  heart-beat  irregular;  the  face 
easily  flushed.  Sleep  becomes  impossible  without  use 
of  the  drug,  and  when  obtained  is  troubled,  and  the  per- 
son awakes  unrested. 

In  later  stages,  the  blood  is  seriously  altered.  Its 
coloring  matter  is  dissolved  out  of  the  corpuscles  into 
the  plasma  (p.  135),  and  then  soaks  through  the  walls  of 
the  capillary  vessels,  causing  purplish  patches  on  the  skin. 

If  the  chloral-taking  be  stiK  continued,  death  results 
from  impovished  blood,  weakened  heart,  or  paralysis  of 
the  nervous  system.  Not  unfrequently,  chloral-takers 
unintentionally  commit  suicide  by  indulging  in  too  large 
doses. 

8.  Bromides. — The  drugs  included  under  this  name, 
resemble  chloral  and  its  compounds  in  that  they  were 
once  regarded  as  safe  soothers  of  the  nervous  system  and 
promoters  of  sleep,  that  physicians  have  now  learned  that 
they  are  very  dangerous  when  frequently  used,  and  that 
the  general  public  still  believe  them  safe,  and  often  use 
them  without  a  doctor's  advice.  They  are  very  valuable 
medicines  in  some  circumstances,  but  may  do  nearly  as 
much  harm,  when  taken  indiscreetly,  as  opium  or  chloral. 
Some  mothers  and  nurses  who  have  learned  the  danger 
of  paregoric  and  soothing  syrups,  now  give  bromides 
instead  to  restless  infants.  The  bromide  may  not  be  so 
dangerous  as  the  opiate,  but  it  should  never  be  given 
except  on  a  doctor's  prescription. 

chloralism.     What  are  the  symptoms  in  more  advanced  chloralism? 
What  in  the  latest  stages  ? 

8.  In  what  do  bromides  resemble  chloral  ?  What  are  the  dangers 
of  using  them  ?  What  precautions  are  necessary  ? 


TOBACCO.  221 

9.  Tobacco  is  often  indulged  in  for  the  sake  of  soothing 
the  nervous  system  or  lessening  the  feeling  of  mental 
fatigue  or  worry.     It  also  decreases  the  oxidations  of  the 
body,  and    its  wasting,  and  so  enables   it   to  get  along 
with  less  food;  it  may  in  this  way  be  useful  to  a  starv- 
ing or  ill-fed  person.     It  contains  a  small  amount  of  an 
active  principle,  nicotin^  which   is  a  powerful  poison.     A 
few  drops  of  pure  nicotin  will  cause  rapid  death  by  para- 
lyzing the  heart.     When  tobacco  is  smoked,  some  of  the 
nicotin  is  burned;  but  vapors  containing  ammonia  are 
formed,  and  these  irritate  the   mouth  and  throat.     The 
ill  effects  of  smoking  are  thus,'  in  part,  general — due  to 
absorbed  nicotin;   and  in  part  local — due  to   irritating 
matters  in  the  smoke.     It  cannot  be  denied   that  many 
persons  consume  a  good  deal  of  tobacco  without  being 
much  harmed  by  it.     But  it  does  no  one  any  good  unless 
he  cannot  get  sufficient  food,  or  his  nervous  system  is  so 
diseased  or  irritable   that  it  needs  soothing.     One  gen- 
eral rule  may  be  laid  down  without  fear  of  contradiction: 
tobacco  is  always  very  injurious  to  those  whose  bodies  are  not 
yet  fully  developed. 

10.  The  Local  Action  of  Tobacco  is  at  first  manifested  by 
an    increased    flow   of   saliva.     After   some   practice   in 
smoking  this  effect  ceases,  and  is  succeeded  by  a  feel- 
ing of  dryness  in  the  mouth,  which  often  leads  to  indul- 
gence   in    alcoholic    drinks.      In    this    perhaps    lies    the 
greatest  danger   from    tobacco.     The   habitual    smoker 
often  suffers  from  what  is  well  known  to  physicians  as 

9.  Why  is  tobacco  indulged  in  ?     When  may  its  use  be  beneficial  ? 
What  is  said  of  nicotin  ?     What  becomes  of  it  when  tobacco  is  smoked  ? 
The  ill  effects  of  smoking  ?     What  general  rule  may  be  safely  stated  ? 

10.  How  does  the  local  action  of  tobacco  first  show   itself?     How 
is  this  changed  by  practice  in  smoking?     Point  out  one  of  the  chief 


222  ACTION  OF   TOBACCO. 

"  smoker's  sore  throat."  This  is  accompanied  by  a  hack- 
ing cough,  and  often  with  difficulty  in  speaking  and  some 
deafness.  Cure  is  impossible  unless  smoking  is  given 
up. 

The  smoke  of  the  paper  in  which  cigarettes  are  rolled 
especially  irritates  the  throat  and  larynx.  So  far  as 
these  organs  are  concerned,  a  cigarette  is  the  most  inju- 
rious form  in  which  tobacco  can  be  smoked. 

11.  The  General  Action  of  Tobacco. — The  absorption  of 
nicotin  and  other  substances  contained  in  tobacco,  is  apt 
to  interfere  with  the  proper  development  of  the  red  cor- 
puscles of  the  blood.  This,  as  you  have  learned  (p.  137), 
is  a  very  serious  evil,  because  these  corpuscles  have  to 
carry  oxygen  all  through  the  body  for  use  by  the  differ- 
ent organs.  As  a  result  of  their  deficient  quantity,  not 
only  does  the  skin  grow  pale,  but  all  the  organs  do  poor 
work.  The  muscles  become  feeble;  the  stomach  digests 
badly;  the  heart  is  weakened  and  subject  to  attacks  of 
palpitation;  and  the  eyesight  very  often  impaired.  In 
general,  there  is  produced  a  feeling  of  lassitude  and  in- 
disposition to  exertion  of  any  kind  that,  in  view  of  the 
heavy  odds  a  man  has  to  contend  against  in  the  struggle 
of  life,  may  prove  the  handicap  that  causes  his  failure. 
If  success  in  life  be  an  aim  worth  striving  for,  it  is  surely 
unwise  to  shackle  one's  self  with  a  habit  which  cannot 
promote  and  may  seriously  jeopardize  it. 

dangers  from  tobacco.  What  is  smoker's  sore  throat  ?  By  what  ac- 
companied ?  What  necessary  for  cure  ?  What  is  said  of  cigarettes? 
II.  Action  of  absorbed  nicotin  on  the  blood?  Why  serious  ?  Ac- 
tion of  nicotin  on  the  muscles?  The  stomach?  The  heart?  The 
eyesight  ?  What  is  said  of  its  effects  in  general  ? 


CHAPTER   XXI. 
THE   SENSES. 

1.  Common  Sensation  and  Special  Senses. — Each  of  us 
has  a  great  many  fee/ings,  or  sensations,  of  different  kinds. 
We  may  be  hungry  or  thirsty  or  tired  or  suffer  pain  in 
a  variety  of  ways.  Such  sensations  as  these  tell  us 
about  our  own  bodies.  Hunger  warns  us  to  eat,  nausea 
or  "sickness"  that  the  stomach  is  not  in  a  condition  to 
digest,  pain  that  some  part  is  diseased  or  injured  and 
needs  attention.  All  these  kinds  of  feeling  are  named 
common  sensations. 

Other  kinds  of  sensations  enable  us  to  learn  about 
things  outside  of  our  bodies,  and  to  perceive  and  use  ob- 
jects in  the  world  around  us.  These  sensations  are 
known  as  the  "  special  senses;"  they  include  sight,  hear- 
ing, smell,  taste,  and  touch,  which  are  commonly  spoken 
of  as  "  the  five  senses."  To  these  we  should  add  the 
temperature-sense,  which  often  enables  us  to  learn  that 
^something  is  hot  or  cold  without  touching  it  or  seeing 
it.  These  senses  have  been  well  called  the  "  gateways  of 
knowledge,"  because  without  them  the  mind  would  have 
to  remain  in  complete  ignorance  of  the  world  and  uni- 
verse in  which  we  live. 

i.  How  do  we  learn  the  needs  of  our  own  bodies?  Examples?  What 
are  these  feelings  called?  What  is  the  use  of  the  special  senses? 
Name  the  "  five  senses."  What  is  the  temperature  sense  ?  Why  are 
the  senses  called  the  gateways  of  knowledge  ? 


224         SENS  ATI  OX   DEPENDS  ON    THE   BRAIN. 

2.  All  Kinds  of  Sensation  Depend  on  the  Brain. — You 

have  already  learned  that  when  the  nerve-fibres  of  the 
foot  are  cut  anywhere  on  their  way  to  the  brain,  the  foot 
loses  feeling  (p.  199).  This  is  true  of  every  other  part 
of  the  body  which  has  feeling,  whether  it  be  merely  a 
part  possessing  some  common  sensation,  or  an  organ  of 
one  of  the  special  senses.  Also,  if  the  brain  be  acted  upon 
by  chloroform  or  ether,  or  certain  parts  of  it  be  seriously 
diseased  or  injured,  feeling  is  lost,  although  the  nerves 
and  the  sense-organs  may  be  quite  unaffected.  We  thus 
learn  that  all  feeling  is  due  to  some  change  in  the  brain. 
Usually,  when  we  have  a  sensation,  whether  of  sight, 
hearing,  pain,  or  any  other  kirfU,  it  is  due  to  the  fact  that 
some  sensory  nerve  (p.  196)  has  been  set  at  work,  and 
has  carried  a  message  to  the  brain.  This  message  has 
then  set  at  work,  or  excited,  a  part  of  the  brain,  which 
makes  us  see  or  smell;  and  so  on.  The  mind  has  learned 
from  what  parts  of  the  body  these  messages  to  the  brain 
usually  start,  and  we  have  come  to  think  of  each  kind  of 
feeling  as  being  in  the  organ  or  place  from  which  the 
message  starts,  and  not  in  the  brain  itself.  When  the 
eye  is  closed  we  do  not  see,  so  we  think  the  sense  of 
sight  is  in  the  eye.  Yet  it  really  is  in  the  brain:  all  that 
the  eye  does  is,  when  light  acts  on  it,  to  send  messages 
along  its  nerve  to  the  brain,  and  set  to  work  that  part  of 
the  brain  which  has  feelings  of  sight;  and  so  it  is  with 
our  other  senses. 

2.  What  results  when  all  the  nerve-fibres  coming  from  any  part  of 
the  body  which  has  feeling,  are  cut  ?  How  may  loss  of  feeling  be 
caused  without  affecting  the  sense-organs  or  the  nerves  ?  What  is 
thus  proved  ?  To  what  is  a  sensation  usually  due  ?  What  happens 
when  the  message  sent  by  the  sensory  nerve  reaches  the  brain  ? 
How  has  the  mind  come  to  connect  certain  feelings  with  certain  parts 
of  the  body  ?  Illustrate.  What  sometimes  happens  as  regards  sen- 
sations in  disease  ?  Results  ? 


THE    ORGAN  OF  SIGHT.  22$ 

Sometimes  in  disease,  the  parts  of  the  brain  which  give 
us  feelings  are  excited  without  waiting  for  any  message 
brought  in  along  a  sensory  nerve.  Then  the  person  be- 
comes delirious  or  suffers  from  delusions.  He  sees  and 
hears  and  smells  things  which  do  not  really  exist;  but 
to  his  mind  they  are  just  as  real  as  if  they  did  actually 
exist,  and  were  acting  on  his  sensory  nerves  so  as  to  ex- 
cite the  parts  of  the  brain  which  feel. 

3.  Why  the  Eye  is  the  Organ  of  Sight.— In  the  eyes  there 
are  thousands  of  nerve-fibres,  each  of  which  has  a  little 
"  tip"  or  end  on  it  which  is  so  made  as  to  be  very  easily 
acted  on  by  light.     Any  light,  as  from  the  sun  or  a  lamp 
or  candle,  which  comes  direct,  or  is  first  reflected  from 
some  object,  and  reaches  one  of  these  peculiar  little  ends, 
excites   it,  and   the  end  in   turn  excites   the  nerve-fibre 
joined  to  it,  and  this  fibre  then  carries  up  some  message 
to  the  part  of  the  brain  which  gives  us  feelings  or  sensa- 
tions of  sight.     If  the  light  comes  direct  it  excites  the 
nerves  in  such  a  way  that  we  see  the  sun  or  lamp  or 
candle.     If  it  comes    bounding   back    from    some  other 
object  which  it  has  struck  on  its  way,  we  see  the  other 
object.     No  other  nerves  than  those  of  the  eye  have  this 
particular  kind  of  tips  on   their  ends,  and  so  light  does 
not  excite  them,  as  it  does  the  nerves  of  the  eye. 

4.  The   Eyeball   (Fig.   55)    is    nearly   as    round    as    a 
marble,  but  is  buried  in  the  eye-socket  and  covered  by 
the  eyelids,  so  that  only  a  small  part  of  its  front  side  can 
be  seen.     On  this  front  part  is  a  round  transparent  win- 
dow, set  in  it,  like  a  pane  of  glass,  to  allow  light  to  get 

3.  What  is  there  on  the  ends  of  the  nerve-fibres  in  the  eye  ?    What 
happens  when  light  reaches  them  ?     Why  cannot  we  use  other  parts 
of  the  body  for  seeing  ? 

4.  Describe  the  shape  and  position  of  the  eyeball.     What  is  there 


226  THE  EYEBALL. 

into  it.  To  the  inner  or  deeper  side  of  the  eyeball  is 
attached  the  optic  nerve,  17,  which  runs  to  the  brain, 
and  is  the  nerve  of  sight. 

5.  The  Eyeball  has  Three  Coats,  an  outer,  a  middle,  and 
an  inner. 

The  outer  coat  is  tough  and  strong:  on  the  back  and 


FIG.  55. — The  left  eyeball  in  horizontal  section,  i,  sclerotic;  2,  junction  of 
sclerotic  and  cornea;  3,  cornea;  10,  choroid;  14,  iris;  15,  retina;  17,  optic  nerve; 
26,  27,  28,  are  placed  on  the  lens  ;  29,  vitreous  humor ;  30,  aqueous  humor. 

sides  of  the  eyeball  it  is  opaque,  that  is  to  say,  does  not 
let  light  go  through  it.  A  little  of  it  can  be  seen  be- 
tween the  eyelids,  as  the  "  white  of  the  eye."  The  opaque 
part  of  the  outer  coat  is  named  the  sclerotic  (i,  Fig.  55). 

on  its  front  ?  Where  does  the  optic  nerve  join  it  ?  Where  does  the 
nerve  go?  Function  of  this  nerve? 

5.  What  coats  has  the  eyeball  ?  Nature  of  the  outer.  Describe  the 
sclerotic-  The  cornea,  The  choroid.  The  iris.  The  pupil.  Why 


THE   CO  A  TS   OF   THE  EYE.  22/ 

The  front  part  of  the  outer  coat  is  the  transparent  por- 
tion above  mentioned.  It  is  called  the  cornea  (3). 

The  middle  coat  is  colored.  Its  hinder  portion,  10,  is 
black,  and  lies  close  against  the  sclerotic;  it  is  called  the 
choroid.  Its  front  part  separates  from  the  outer  coat,  and 
instead  of  lying  close  against  the  cornea,  turns  in  a  little 
way  behind  it,  14,  so  as  to  leave  a  space,  30,  between. 
This  part  of  the  middle  coat  is  called  the  iris.  Its  color 
varies;  we  see  it  through  the  cornea,  and  say  the  eye  is 
brown,  or  blue,  or  gray,  or  black,  according  to  the  color 
of  the  iris.  In  the  middle  of  the  iris  is  a  hole,  the  pupil 
of  the  eye.  It  looks  black,  just  as  a  hole  opening  into  a 
box  whose  inside  was  painted  black  would,  if  you  viewed 
it  from  outside,  although  the  hole  would  let  light  into 
the  box.  The  dark  choroid  answers  to  the  black  paint 
inside  the  box;  in  some  animals,  as  dogs  and  cats,  part 
of  it  is  not  black,  and  so  the  inside  of  the  eyes  of  those 
animals,  seen  through  the  pupil,  often  looks  shining.  In 
bright  light,  the  pupil  becomes  smaller,  so  as  to  protect 
the  nerves  inside  the  eye  from  being  over-stimulated  and 
dazzled:  when  there  is  not  much  light  the  pupil  becomes 
larger.  If  you  stand  in  front  of  a  mirror  and  close  your 
eyes  for  half  a  minute,  and  then  open  them  and  let  light 
get  into  them,  you  can  watch  your  pupils  getting 
smaller. 

The  inside  coat  of  the  eyeball  is  the  retina,  15.  It  is 
very  thin,  and  is  transparent  so  that  the  dark  color  of 
the  choroid  shows  through  it.  The  retina  only  lines  the 
hinder  half  of  the  eyeball.  It  is  the  sensitive  part  of 

does  the  pupil  look  black  ?  What  is  said  of  its  expansion  and  con- 
traction ?  How  can  you  see  the  contraction  of  your  own  pupil  ?  What 
is  the  retina?  Describe  it.  Its  position  ?  Of  what  does  it  consist  ? 
Illustrate  the  connection  of  optic  nerve  and  retina. 


228  THE   CONTENTS  OF   THE  EYEBALL. 

the  eye,  and  consists  of  the  spread-out  fibres  of  the  optic 
nerve,  and  the  peculiar  tips  or  "  end  organs"  joined  to 
them.  If  you  should  take  a  cord,  and  fray  out  its  threads 
at  one  end,  and  spread  them  out  on  all  sides,  the  cord 
would  answer  to  the  optic  nerve,  and  the  spread-out 
threads  to  its  fibres  in  the  retina,  except  that  each 
thread,  in  order  to  make  the  resemblance  greater,  ought 
to  have  a  very  small  rod  or  cone  easily  excited  by 
light,  attached  to  its  end. 

6.  The  Interior  of  the  Eyeball  is  filled  up  by  liquid  or 
jelly-like   matters,  surrounded  by  its  coats,  as  the  pulp 
of   an   orange  is  surrounded  by  the  rind.     These  sub- 
stances are  all  transparent;    they  guide  to  the  retina, 
light  which  enters  the  eye  through  the  cornea  and  pupil. 
They  are  three  in  number,     (i)  The  crystalline  lens,  26, 
27,  28,  just  behind  the  iris.     It  is  soft  and  jelly-like.     (2) 
The  aqueous   (watery)   humor,  30,  a  watery  liquid  be- 
tween the  crystalline  lens   and    the   inner   side   of   the 
cornea.     (3)  The  vitreous  (glassy)  humor,  29,  behind  the 
crystalline  lens,  a  soft  jelly  filling  up  all  the  back  part  of 
the  cavity  of  the  eyeball. 

7.  The  Use  of  Aqueous  Humor,  Lens,  and  Vitreous  Humor 
is  to  gather  the  rays  or  lines  of  light  which  enter  the  eye, 
and  so  bend  and  direct  them,  that  all  those  starting  from 
one  point  outside  the  eye  meet  again  in  one  point  on  the 
retina,  and  excite  the  same  nerve-fibre.     This  enables  us 
to  see  things  distinctly,  because  an  exact  image  of  the 
thing  looked   at  is   made  on  the  retina.     In  Fig.  56,  O 
answers  to  the  lens  of  the  eye;  Z>,  E,  is  the  object  looked 

6.  How  is  the  interior  of  the  eyeball  filled  ?     Use  of  these  sub- 
stances ?    Their  number  ?     Names  ?     Describe  each. 

7.  What  is  the  use  of  aqueous  humor,  vitreous  humor,  and  lens  ? 
How  does  their  action  enable  us  to  see  distinctly  ?     How  is  the  image 


HOW  IMAGES  ARE  MADE   ON   THE  RETINA.     22Q 

at;  and  d,  e,  its  image  on  the  retina.  The  image  is  much 
smaller  than  the  object,  and  is  wrong  side  up,  but  the 
mind  has  learned  by  experience  to  understand  it  in  the 
right  way. 


FIG.  56 —Illustrating  the  formation  behind  a  convex  lens  of  a  diminished  and 
inverted  image  of  an  object  placed  in  front  of  it. 

8.  Short-Sight  and  Long-Sight. — When  you  use  a  tele- 
scope or  an  opera-glass  to  look  at  any  object,  you  have  to 
focus  it.  The  arrangement  which  will  enable  you  to 
use  it  for  seeing  near  objects  distinctly,  must  be  changed 
before  you  can  use  the  glass  for  seeing  things  farther 
off.  In  our  eyes,  the  lens  does  this  focusing;  it  changes 
according  as  we  look  at  near  or  distant  things.  In  per- 
sons with  good  eyes  (A,  Fig.  57),  the  lens  can  accurately 
focus  on  the  retina,  images  of  very  distant  objects,  and 
also  of  things  within  seven  or  eight  inches  of  the  eye. 
In  other  persons  (JB),  the  eyeball  is  too  long  from  front 
to  back,  and  the  lens  cannot  focus  on  the  retina  the 
rays  or  lines  of  light  coming  from  distant  objects:  such 
persons  are  short-sighted.  They  can  see  very  distinctly 
things  near  the  eye,  but  more  distant  objects  seem 

of  an  object  looked  at,  depicted  on   the  retina?    Why  do  we  see  it 
rightly  ? 

8.  How  is  a  telescope  arranged  for  seeing  near  or  distant  objects  ? 
How  do  our  eyes  focus  what  they  look  at?  What  is  said  of  this 
power  in  good  eyes  ?  Why  are  some  eyes  short-sighted  ?  Why  are 
others  long-sighted? 


23°  HYGIENE   OP   THE  EYES. 

blurred  and  indistinct.  The  opposite  defect  is  long-sight. 
In  those  who  suffer  from  it,  the  eyeball  is  so  flat  that  the 
lens  cannot  focus  on  the  retina  rays  of  light  coming 
from  a  near  object  (C,  Fig.  57). 


FIG.  57.— Diagram  illustrating  the  path  of  parallel  rays  of  light  after  entering 
a  healthy,  well-shaped  eye  (A),  a  short-sighted  eye  (.5),  and  a  long-sighted  eye  (C). 

9.  Hygiene  of  the  Eyes. — Looking  directly  at  very 
bright  objects,  as  the  sun  or  an  electric  lamp,  dazzles 
and  injures  the  eyes;  so  does  sudden  change  from  dark- 
ness to  light.  On  first  waking,  the  eyes  should  be  some- 
what gradually  accustomed  to  bright  light.  The  ill 
effects  of  such  changes  are  much  less  serious  than  the 
harm  that  may  be  done  by  using  the  eyes  when  there  is 
not  enough  light  to  see  clearly.  Frequent  reading  or 

9.  What  is  the  effect  on  the  eyes  of  looking  at  very  bright  lights  ? 
Why  should  they  be  gradually  accustomed  to  light  after  sleeping? 
What  is  even  more  injurious  to  the  eyes  than  sudden  changes  from 


EYELIDS.— TEARS.  231 

sewing  in  such  feeble  light  that  the  eyes  feel  strained, 
will  certainly  injure  them  permanently. 

Long-sight  and  short-sight  are  not  diseases.  They 
are  due  to  the  fact  that  the  eyeball  is  not  perfectly 
shaped,  but  it  may,  nevertheless,  be  perfectly  healthy. 
Both  defects  are  easily  remedied  by  proper  spectacles 
or  eye-glasses.  If  neglected,  they  lead  not  only  to  dis- 
ease of  the  eye  itself,  but  to  headaches,  and  other 
symptoms  of  nervous  disorder. 

10.  The  Eyelids  are  folds  of  skin  moved  by  muscles 
so  as  to  cover  or  uncover  the  front  of  the  eyeball,  or,  as 
we   ordinarily  say,  to   shut  or  open   the  eye.     Opening 
along  the  edge  of  each  eyelid,  are  twenty  or  thirty  small 
glands.     Their  secretion  is  greasy  and  keeps  the  tears 
from  flowing  over  the  edge  of  the  eyelids,  except  when 
they  are   secreted  in  large  quantity.     The  eyelid-secre- 
tion is  sometimes  too  abundant,  and  then  appears  as  a 
yellowish  matter  along  the  edges  of  the  eyelid.     It  often 
dries  during  the  night  and  causes  the  lids  to  be  glued 
together  in  the  morning. 

11.  Tears  are  secreted  by  the  tear  or  lachrymal  glands, 
which  lie,  one  in  each  eye-socket,  above  and  to  the  outer 
side  of  the  eyeball.     They  are  poured  on  the  front  of  the 
eye  by  the  tear-ducts  which  open  on  the  deeper  or  inner 
side  of  the  upper  eyelid,  near  its  outer  corner.     Tears 
are  secreted  all   the    time,    but   usually  only    in    small 
quantity.     Winking  spreads   them  all  over  the  front  of 


darkness    to    bright  light?     How  may    short  sight  or  long-sight   be 
remedied  ?     What  happens  if  they  are  neglected  ? 

10.  What  are  the  eyelids ?     What  open  along  their  edges?     Use  of 
these  glands  ?     Why  are  the  eyelids  sometimes  glued  together  in  the 
morning? 

11.  Where  are  the  tear-glands?  Where  do  these  ducts  open?   How 


HEARING. 


the  eyeball,  and  they  keep  it  moist.  What  remains  is 
drained  off  by  canals  which  run  from  the  inner  corner 
of  each  eyelid  to  the  inside  of  the  nose,  from  which  the 
liquid  flows  into  the  pharynx,  and  is  swallowed.  In 
weeping,  the  tears  are  secreted  faster  than  these  canals 


FIG.  58.— Semi-diagrammatic  section  through  the  right  ear.  M,  concha.  G.  ex- 
ternal auditory  meatus.  7",  tympanic  or  drum  membrane.  P,  Tympanum.  Ex- 
tending from  T  to  o  is  seen  the  chain  of  tympanic  bones.  /?,  Eustachian  tube. 
K,  B,  S,  bony  labyrinth:  V,  vestibule;  B,  semicircular  canal;  S,  cochlea,  b,  I,  /', 
membranous  semicircular  canal  and  vestibule.  A,  auditory  nerve  dividing  into 
branches  for  vestibule,  semicircular  canal,  and  cochlea. 

can  carry  them  off,  so  they  flow  over  the  lower  eyelids 
and  trickle  down  the  face. 

12.  Hearing. — The  ear  consists  of  three  portions,  known 
as  the  external  ear,  the  middle  ear  or  tympanum  (drum),  and 
the  internal  ear  or  labyrinth.  The  labyrinth  is  so  named 

are  they  spread  over  the  eye  ?     Where  are  they  usually  carried  from 
the  eye?     Why  do  they  trickle  down  the  face  in  weeping? 

12.   What  are  the  three  main  portions  of  the  ear?      Why  is   the 


THE  EAR.  233 

because  it  has  many  winding  passages  in  it.  The  nerves 
of  hearing  are  the  two  auditory  nerves.  One  runs  to  each 
ear  from  the  brain,  and  its  fibres  end  in  the  labyrinth, 
in  connection  with  peculiar  very  small  organs  which  are 
easily  excited  by  slight  shaking,  and  then  excite  the 
fibres  of  the  auditory  nerve.  Everything  that  gives  out 
sound  shakes  or  vibrates,  and  sets  the  air  all  round  it 
shaking.  The  use  of  the  outer  ear  and  middle  ear  is  to 
take  up  the  vibrations  of  the  air  and  pass  them  on  to  the 
organs  on  the  ends  of  the  nerve-fibres  in  the  inner  ear. 

13.  The  External  Ear  consists  of   the   expansion  (M, 
Fig.  58)  seen  on  the  exterior  of  the  head,  called  the  con- 
cha (shell),  and  a  passage  leading  in  from  it,  the  external 
auditory  meatus,  G.     This  passage  is  closed  at  its  inner  end 
by  the  tympanic,   or  drum,  membrane,  T.     It  is  lined  by  a 
prolongation  of  the  skin,  through  which  numerous  small 
glands,  secreting  the  wax  of  the  ear.  open. 

14.  The  Tympanum,  or  drum-chamber  of  the  ear  (Fig. 
59  and  P,  Fig.  58),  is  a  small  cavity  in  one  of  the  bones 
on  the  side  of  the  skull.     It  is  closed  externally  by  the 
drum-membrane.     From   its    inner   side    the   Eustachian 
tube  (R,  Fig.   58)  proceeds  and  opens  into  the   pharynx 
(g,  Fig.  30).     This   tube  allows  air  from   the  throat  to 
enter  the  tympanum,  and  serves  to  keep  equal  the  pres- 
sure of    the  air  on   each   side  of  the  drum-membrane. 
Three  small  bones  (Fig.  59)  stretch  across  the  tympanic 
cavity  from  the  drum-membrane  to  the  labyrinth;  they 


labyrinth  so  named?  What  are  the  auditory  nerves?  What  is  at- 
tached to  ends  of  their  fibres  in  the  ear?  How  used  in  helping  us  to 
hear  ?  Use  of  outer  and  middle  ear  ? 

13.  Of  what  does  the  external  ear  consist?    What  is  found  at  the 
inner  end  of  its  passage  ?     How  is  the  passage  lined  ? 

14.  Describe  the  tympanum.     What  is  the  Eustachian  tube?     Its 


234  THE  INTERNAL  EAR. 

pass  on  to  the  labyrinth,  the  vibrations  of  the  membrane, 
produced  by  vibrations  of  the  air.  The  outmost  bone 
is  the  malleus  or  hammer-bone,  L  j  the  inmost,  the  stapes 
or  stirrup-bone,  S ;  and  the  one  between,  the  incus  or  anvil- 
bone,  H. 


FIG.  59. — The  tympanic  cavity,  C,  C,  and  its  bones,  considerably  magnified.  G, 
the  inner  end  of  the  external  auditory  meatus,  closed  internally  by  the  conical  tym- 
panic membrane;  L,  the  malleus,  or  hammer-bone;  //,  the  incus,  or  anvil-bone; 
S,  the  stapes,  or  stirrup-bone. 

15.  The  Internal  Ear,  or  Labyrinth,  consists  of  cham- 
bers and  tubes  hollowed  out  in  the  inner  part  of  the 
temporal  bone,  T,  Fig.  6,  and  containing  thin  bags  and 
tubes,  filled  and  surrounded  by  watery  liquid.  Inside 
these  bags  and  tubes  the  fibres  of  the  auditory  nerve 
end.  Its  middle  chamber,  called  the  vestibule  (  V,  Fig.  58), 
has  an  opening,  the  oval  foramen,  o,  in  its  outer  side,  into 

use  ?     Number  and    arrangement  of    the  bones  in   the   tympanum  ? 
Their  use  ?     Names  and  position  of  these  bones  ? 

15.  Of  what  does  the  internal  ear  consist  ?  Where  do  the  fibres  of 
the  auditory  nerve  end  ?  Name  of  the  middle  chamber  of  the  internal 
ear?  Where  is  the  oval  foramen,  and  what  fits  into  it?  Where  are 


HYGIENE   OP   THE  EAl  23$ 

which  the  inner  end  of  the  stapes,  or  stirrup-Done,  fits. 
Behind,  the  vestibule  opens  into  three  semicircular  canals, 
one  of  which  is  shown  at  B,  and  in  front  into  a  spirally 
coiled  tube,  S,  the  cochlea. 

When  shakings  or  vibrations  of  the  air  make  the  tym- 
panic membrane  vibrate,  it  shakes  the  tympanic  bones; 
the  stapes,  vibrating  in  the  oval  foramen,  then  shakes 
the  liquids  in  the  labyrinth,  and  sets  up  vibrations  in 
them,  which  excite  the  endings  of  the  auditory  nerve. 
The  stimulated  auditory  nerve  then  conveys  a  nervous 
impulse  to  the  part  of  the  brain  concerned  with  hearing 
and  excites  it,  and  a  sensation  of  sound  results. 

16.  Hygiene  of  the  Ear. — The  outer  parts  of  the  ear 
are  less  tender  than  the  eye,  and  are  more  often  injured 
by  unnecessary  meddling.  When  the  ear  is  healthy,  its 
wax  dries  up  into  scales  and  is  shed  in  proper  quantity. 
Some  of  it  is  necessary  to  protect  the  inner  parts  of  the 
ear.  Rubbing  it  out  by  stiff  objects,  not  only  removes 
it  too  fast,  but  may  cause  inflammation  of  the  tympanic 
membrane.  If  the  wax  is  clearly  excessive,  or  if  there  is 
any  running  from  the  ear,  it  is  wisest  to  consult  a  physi- 
cian at  once.  No  stiff  rod  should  ever  be  put  into  the 
ear,  except  by  a  skilled  person.  The  tympanic  mem- 
brane is  very  thin  and  may  easily  be  torn.  Young  chil- 
dren often  put  such  things  as  peas  and  small  beans  in 
their  ears.  If  they  do  not  come  out  very  easily,  get  a 
doctor  to  rejnove  them.  In  any  such  case,  do  not  pour 

the  semicircular  canals  ?  The  cochlea  ?  Describe  how  the  endings  of 
the  auditory  nerve  are  excited  by  vibrations  of  the  air.  What  results 
when  the  auditory  nerve  is  stimulated  ? 

16.  Why  are  the  ears  more  often  injured  than  the  eyes  by  meddling  ? 
What  happens  to  the  wax  of  the  ear  in  health  ?  Why  is  some  wax 
necessary  ?  What  may  result  from  removing  it  ?  What  should  be 
done  when  there  is  any  running  from  the  ear?  When  a  child  has  put 


TOUCH. 

water  into  the  ear;  it  causes  a  pea  or  bean  to  swell,  and 
makes  its  removal  very  difficult. 

Deafness  may  be  caused  in  many  ways:  by  disease  of 
the  auditory  nerve,  by  disease  of  the  labyrinth  or  of  the 
tympanum,  by  stoppage  of  the  outer  passage  by  wax  or 
some  foreign  object,  or  by  inflammation  and  swelling  of 
the  membrane  lining  the  Eustachian  tubes.  Swollen 
tonsils  (p.  101).  or  a  cold  which  has  settled  on  the  throat, 
or  smoking,  very  often  cause  deafness  in  the  way  last 
mentioned.  If  the  auditory  nerve  or  the  internal  ear  are 
at  fault,  the  deafness  may  be  incurable.  In  most  other 
cases,  cure  is  possible  with  medical  aid.  In  the  case  of 
a  cold,  the  cure  usually  occurs  of  itself  if  you  have  a 
little  patience. 

17.  Touch,  or  the  Pressure-Sense. — Many  sensory  nerves 
end  in  the  skin,  and  through  it  we  get  several  kinds  of 
sensation;  touch,  heat  and  cold,  and/0/«y  and  we  can  with 
more  or  less  accuracy  say  from  what  parts  of  the  skin 
they  have  come.     The  interior  of  the  mouth  also  pos- 
sesses these  feelings.    Through  touch,  we  recognize  pres- 
sure on  the  skin,  and  the  force  of  the  pressure;  the  soft- 
ness or  hardness,  roughness  or  smoothness,  of  the  body 
producing  it;  and  the  form  of  this  body,  when  it  is  not 
too  large  to  be  felt  all  over.     The  nerves  of  touch  are 
very   numerous.      A   great   many   of   them    end    inside 
papillae  of  the  dermis(p.  63). 

18.  The  Delicacy  of  the  Sense  of  Touch  is  very  different 

some  foreign  body  into  its  ear  ?  Name  some  of  the  causes  of  deaf- 
ness. How  may  swollen  tonsils  cause  deafness  ?  When  is  deafness 
apt  to  be  incurable  ? 

17.  What  sensations  do  we  get  from  the  skin  ?  What  other  part 
of  the  body  gives  rise  to  these  sensations?  What  do  we  recognize 
through  touch  ?  Where  do  many  of  the  nerves  of  touch  end  ? 


TEMPERA  TURE-SENSE. 

on  different  parts  of  the  skin.  It  includes  two  dis- 
tinct things,  which  are  often  confounded.  In  the  strict 
sense  of  the  words,  touch  is  most  delicate  where  the 
smallest  pressure  can  be  felt.  In  this  meaning,  the  sense 
of  touch  is  most  acute  on  the  forehead  and  temples, 
where  a  lighter  weight  can  be  felt  than  on  any  other 
part  of  the  skin.  Usually,  however,  by  delicacy  of  touch 
is  meant  the  accuracy  with  which,  the  eyes  being 
closed,  we  can  tell  the  exact  point  of  the  skin  which  is 
touched.  In  this  meaning,  the  sense  of  touch  is  most 
acute  on  the  tip  of  the  tongue,  the  edge  of  the  lips,  and 
the  ends  of  the  fingers.  If  the  blunted  points  of  a  pair 
of  compasses,  closed  to  within  one  twelfth  of  an  inch,  be 
gently  laid,  at  the  same  moment,  on  a  finger-tip,  we  dis- 
tinguish between  them  and  feel  two  touches,  while  on 
the  back  of  the  neck  they  must  be  more  than  an  inch 
apart  before  we  can  distinguish  them.  The  papillae  of 
the  dermis  are  always  numerous  where  the  distinguish- 
ing power  is  great. 

19.  The  Temperature-Sense. — By  this  is  meant  our  fac- 
ulty of  perceiving  cold  and  heat;  and,  with  the  help  of 
these  sensations,  of  perceiving  whether  things  are  cold 
or  hot.  Its  organs  are  the  whole  skin,  the  mucous  mem- 
brane of  mouth,  pharynx,  and  gullet,  and' of  the  entry  of 
the  nose.  Burning  the  skin  will  cause  pain,  but  not  a 
true  temperature-sensation,  which  is  quite  as  different 
from  pain  as  touch  is. 

1 8.  What  is  meant  by  delicacy  of  touch  in  the  strict  sense  of  the 
words?  Where  is  it  most  acute  ?  What  is  usually  meant  by  delicacy 
of  touch  ?  Where  is  it  most  acute  ?  Give  an  illustration  of  its  variation 
on  different  regions  of  the  skin.  Where  are  the  papillae  numerous? 

jo,.  What  is  the  temperature-sense  ?    What  are  its  organs  ? 


238  SMELL  AND    TASTE. 

20.  Smell. — The  organ  of  smell,  or  the  olfactory  organ, 
consists  of  the  mucous  membrane  lining  the  upper  por- 
tions of  the  two  nostril-cavities.     Part  of  it  is  shown  at 
o  and/,  Fig.  42.     The  nerves  of  smell  are  the  two  olfac- 
tory nerves,  one  of  which  runs  from  each  nostril-chamber 
to  the  brain. 

21.  Odorous  Substances  frequently  act  powerfully  when 
present  in  very  small  quantity.     A  grain  or  two  of  musk 
kept  in  a  room  will  give  the  air  in  it  an  odor  for  years, 
and  yet  at  the  end  will  hardly  have  diminished  in  weight, 
so  infinitesimal  is  the  quantity  given  off  from  it  to  the 
air  and  able  to  excite  the  sense  of  smell. 

22.  Taste. — The  organ  of  taste  is  the   mucous   mem- 
brane on  the  upper  side  of  the  tongue,  and  the  under 
side  of  the  soft  palate  (p.  101),  The  mucous  membrane  of 
the  tongue  presents  innumerable  elevations  or  papillae. 
Some  are  organs  of  touch,  for  the  tongue  has  the  sense 
of  touch  as  well  as  of  taste.     Others  contain  the  endings 
of  nerve-fibres  which,  when  excited,  stimulate  the  taste- 
centres  in  the  brain  and  cause  sensations  of  taste. 

Many  so-called  tastes  (flavors)  are  really  smells  ; 
particles  of  substances  which  are  being  eaten  reach  the 
nose  through  the  pharynx  (see  Fig.  42),  and  arouse  smell- 
sensations  which,  because  they  accompany  the  presence  of 
objects  in  the  mouth,  we  take  for  tastes.  Such  is  the  case 
with  most  spices;  when  the  nasal  chambers  are  blocked 
during  a  cold  in  the  head  (p.  154),  or  closed  by  holding 

20.  Of  what  does  the  olfactory  organ  consist? 

21.  Illustrate  the  efficiency,  so  far  as  producing  smell-sensations  is 
concerned,  of  a  very  small  quantity  of  an  odorous  substance. 

22.  What   is   the  organ  of  taste  ?     What  is  found  on  the  mucous 
membrane  of  the  tongue  ?     What  are  the  uses  of  its  papillae  ? 

What  are  many  so  called  tastes  ?     Illustrate. 


DEPENDENCE    OF  FLAVOR   ON  SMELL.          239 

the  nose,  the  so-called  "  taste"  of  spices  is  not  perceived 
when  they  are  eaten.  If  cinnamon,  e.g.,  is  chewed  under 
such  circumstances,  the  only  sensation  felt  is  a  sort  of  hot 


FIG.  60.— The  upper  surface  of  the  tongue,    i,  2,  circumvallate    papillae;    3, 
fungiform  papillae  ;  4,  filiform  papillae. 

feeling  in  the  mouth.  Some  of  the  most  nauseous  medi- 
cines have  really  no  taste,  or  very  little.  If  the  nose  be 
held,  they  can  be  swallowed  without  disgust 


CHAPTER  XXII. 

THE  ACTION  OF  ALCOHOL  ON  BODY,  MIND,  AND 
CHARACTER. 

1.  Introductory. — We  hope  that  the  boys  and  girls  for 
whom  this  book  has  been  written,  with  its  statement  of 
the  structure  and  working  of  the  parts  of  the  human 
body,  and  the  rules  which  must  be  observed  if  health  is  to 
be  kept,  have  had  little  chance  to  gain  experience  of  the 
evils  of  intemperance.  Unhappily,  none  of  us  can  re- 
main long  ignorant  of  them.  All  around  us  are  those 
who  suffer  in  one  way  or  another  from  the  effects  of  alco- 
holic drinks.  We  speak  not  only  of  those  who  them- 
selves indulge  in  them,  but  of  the  far  larger  number 
whose  lives  are  spoiled  by  the  ruin  of  their  natural  pro- 
tectors and  their  loved  ones. 

We  do  not  mean  to  say  that  most  of  those  who  drink 
liquor  are  drunkards,  or  indulge  in  it  to  excess,  in  the 
ordinary  sense  of  the  words;  but  when  we  think  of  the 
great  number  who  daily  take  drinks  containing  alcohol; 
when  we  call  to  mind  the  fact  that  what  is  usually  called 
moderate  drinking,  which  never  makes  a  man  drunk,  is 
often  positively  hurtful,  and  may  alter  for  the  worse 
nearly  every  important  organ  of  the  body;  when  we  re- 

i.  Why  are  we  unlikely  to  remain  ignorant  of  the  evils  of  alcohol- 
drinking?  What  is  said  of  "  moderate"  drinking?  Of  nervous  dis- 
eases due  to  alcohol  ?  Of  its  general  effect  on  human  happiness  ? 


RESULTS   OF  INTEMPERANCE.  241 

member  that  nervous  diseases  are  very  frequently  pro- 
duced by  alcohol,  and  are  more  often  transmitted  by 
parents  to  their  children  than  any  other  class  of  dis- 
eases, assuming  worse  forms  as  they  are  passed  on  from 
generation  to  generation;  when  we  recall  such  facts,  we 
have  no  reason  to  wonder  that  more  disease  and  prema- 
ture death,  more  crime  and  misery,  are  due  to  alcohol 
than  to  bad  drainage,  foul  air,  insufficient  food,  unsuit- 
able clothing,  or  any  other  of  the  subjects  treated  of  in 
an  elementary  text-book  of  physiology  and  hygiene. 

The  habit  of  drinking  is  often  formed  in  ignorance  of 
its  consequences.  Be  warned  and  instructed  in  time,  to 
protect  yourself  and  others  against  it.  Many  of  the  dis- 
eases produced  by  alcohol  come  on  so  gradually  that  they 
are  not  recognized  until  the  will  has  become  too  weak 
to  resist  what  the  appetite  craves. 

The  form  of  disease  depends  on  the  sort  of  drink,  the 
amount,  and  the  constitution.  Some  few  there  are, 
whose  excretory  organs  are  so  active  that  the  alcohol  is 
quickly  passed  out  of  the  body,  and  no  disease,  due  to 
it,  manifests  itself  until  the  close  of,  perhaps,  a  long  life. 
Such  persons  are,  however,  marked  exceptions  to  the 
general  rule,  which  may  be  thus  stated:  prolonged  exces- 
sive use  of  alcoholic  liquors,  leads  surely  to  disease  of  the  body 
and  disease  of  the  mind;  often  to  insanity  and  death. 

2.  Alcoholic  Drinks,  as  you  have  already  learned  (p.  94), 
are  all  such  intoxicating  liquors  as  brandy,  whiskey,  gin, 
rum,  wines,  ales,  beer,  and  cider  ;  also  mixtures  which 

How  is  the  habit  often  formed?  Why  are  the  diseases  caused  by 
it  often  discovered  too  late  ?  On  what  does  the  form  of  disease  de- 
pend ?  Why  do  some  persons  escape  for  a  long  time?  What  is  the 
general  rule  ? 

2.   Name  the  alcoholic  drinks  most  often  used. 


242  ALCOHOL   AS  FOOD. 

contain  them,  as  cordials,  punch,  egg-nogs,  and  many 
"  tonics." 

We  have  studied  their  effects  upon  some  of  the  most 
important  organs  of  the  body  in  turn;  but  in  order  to  fix 
them  more  clearly  in  our  minds,  let  us  review  the  whole 
subject. 

3.  Alcohol  as  a  Food. — Foods  build  tissues;  alcohol  leads 
to   overgrowth   of   some   tissues,  but   not  to  growth  of 
muscle,    brain,    or   gland.      Foods    supply    strength    or 
working  power;  alcohol  stimulates  brain  and  muscle  to 
overwork,  and  as  it  nourishes  neither,  the  final  result  is 
failure    in    strength    and    endurance.      Foods    maintain 
animal  heat;  alcohol  makes  one  feel  warm  for  the  mo- 
ment, but  its  actual   effect  on   the   temperature   of  the 
body  is  to  lower  it  (pp.  96,  97). 

4.  Effects  of  Continued  Use  of  Alcohol  on  Various  Tis- 
sues and  Organs. — These  may  be  summed  up  as  follows: 

Connective  tissue  is  so  increased  in  quantity  that  it 
crushes  and  destroys  parts  which,  when  present  in  only 
healthy  amount,  it  protects  (p.  14). 

The  muscles  have  their  strength,  and  their  power  of 
keeping  a  long  time  at  work,  lessened  (p.  58).  They  are 
also  made  liable  to  chronic  rheumatism  (p.  50). 

The  skin  has  its  vessels  dilated  and  an  excessive  amount 
of  blood  made  to  flow  to  it,  causing  congestion;  and  im- 
pairing that  activity  of  its  glands  necessary  to  maintain 
health  (p.  76). 

The  digestive  organs  in  general  are  often  diseased   in 


3.  What  is  said  of  alcohol  as  regards  the  building  of  tissues  ?     As 
a  strengthener  and  stimulant  ?     In  regard  to  its  effect  on  the  tempera- 
ture of  the  body  ? 

4.  Action  of  alcohol  on  connective  tissue?     On  the  muscles  ?    The 


DISEASES  DUE    TO  ALCOHOL.  243 

consequence  of  the  general  slow  poisoning  of  the  body 
caused  by  alcohol.  The  stomach  and  liver  are  more 
directly  attacked  by  it. 

1.  The   mucous   membrane  of   the    stomach   becomes 
congested,  then  inflamed.     It  fails  to  secrete  gastric  juice 
and  indigestion  results  (p.  130). 

2.  The  true  liver-substance  being  injured  or  destroyed 
by   increased    growth    of    connective    tissue,    the    organ 
becomes  a  shrunken  rough    mass,  unfit  to  perform  its 
important    duties    in    the    nourishment    of    the    body 

(P-  X32). 

The  blood  has  its  power  of  absorbing  and  carrying 
oxygen  decreased,  and  also  its  power  of  clotting.  Hence 
the  temperature  of  the  body  and  its  working  power  are 
lessened,  and  any  wound  is  more  apt  to  bleed  danger- 
ously (p.  161). 

The  arteries  have  their  walls  weakened  so  that  they  be- 
come liable  to  burst  under  the  pressure  of  the  blood 
inside  them  (pp.  161,  162). 

The  heart  has  its  beat  quickened  so  that  it  does  not 
get  enough  rest.  Its  overworked  muscle  thus  does  not 
get  sufficient  nourishment,  and  at  last  becomes  unable 
to  pump  the  blood  along  (p.  162). 

The  respiratory  organs  have  their  lining  mucous  mem- 
brane congested  and  irritated,  increasing  the  liability  to 
colds  and  other  diseases  (p.  184). 

The  kidneys  are  overstimulated,  and  at  last  become 
unable  to  do  properly  their  work  of  removing  nitrogen 
wastes.  Very  often  a  fatal  malady,  named  Bright's  dis- 
ease, is  produced  (p.  189). 

skin  ?  The  digestive  organs  in  general  ?  The  stomach  ?  The  liver? 
The  blood  ?  The  arteries  ?  The  heart  ?  The  respiratory  organs  ? 


244  DISEASES  DUE    TO   ALCOHOL. 

The  brain  and  spinal  cord  are  kept  in  a  chronic  state  of 
congestion*  and  overexcitement.  This  results  at  first 
in  inflammatory  disease  (delirium  tremens);  later  in 
paralysis,  epilepsy,  or  insanity  (pp.  212,  214). 

The  senses  are  dulled,  partly  from  disease  of  the  nerves 
and  nerve-centres,  partly  by  diseased  changes  in  the 
sense-organs. 

No  tippler  probably  ever  suffered  from  all  of  the  dis- 
eases above  mentioned,  and  most  of  them  may  develop 
in  persons  who  are  total  abstainers,  but  some  of  them 
are  pretty  sure  to  develop  in  habitual  drinkers,  and  they 
are  all  more  frequently  due  to  intemperance  than  to 
any  other  single  cause.  It  is  also  well  known  that  in 
any  serious  disease,  the  chances  of  recovery  are  smaller 
in  the  case  of  drinkers. 

5.  Continued  Alcoholic  Indulgence  Causes  Premature  Old 
Age. — Many  of  the  alterations  in  various  tissues  and  or- 
gans above  described  as  brought  about  by  alcohol,  are 
very  like  the  changes  which  naturally  occur  in  old  age. 
When  alcohol  does  not  cause  some  actual  disease,  as 
Bright's  disease,  or  delirium  tremens,  it  often  hastens 
the  ageing  of  the  body.  The  organs  lose  strength  and 
activity,  and  become  old  before  their  time. 

The  kidneys  ?     The  brain  and  spinal  cord  ?    The  senses  ?     How  does 
habitual  drinking  affect  the  ch  uices  of  recovery  from  disease? 

5.  What  does  alcohol  often  do  when  it  does  not  cause  actual  dis- 
ease ? 


*  "  I  once  had  the  unusual  though  unhappy  opportunity  of  observing  the  same 
phenomenon  in  the  brain-structure  of  a  man  who,  in  a  fit  of  alcoholic  excitement, 
decapitated  himself  under  the  wheel  of  a  railway-carriage,  and  whose  brain  was 
instantaneously  evolved  from  the  skull  by  the  crash.  The  brain  it^Hf.  entire,  was 
before  me  within  three  minutes  after  death.  It  exhaled  the  odor  of  spirit  most 
distinctly,  and  its  membranes  and  minute  structures  were  vascular  in  the  extreme. 
It  looked  as  if  it  had  been  recently  injected  with  vermilion.1' — DR.  B.  W.  RICH- 

AKDSON. 


CHARACTER  DESTROYED   BY  INTEMPERANCE.     24$ 

6.  The  Destruction  of  Will  and  Character  by  Alcohol. — 

One  of  the  first  effects  produced  by  alcoholic  drinks 
is  weakening  of  the  control  of  the  will  over  the  actions. 
A  slightly  tipsy  man  laughs  and  talks  loudly,  says  and 
does  rash  things,  is  enraged  or  delighted  without  due 
cause.  If  the  amount  of  alcohol  be  increased,  the 
power  of  the  will  is  further  lessened.  The  muscles 
obey  it  very  imperfectly,  so  speech  becomes  indistinct 
and  the  legs  unsteady.  At  the  same  time,  the  reason 
is  so  weakened  that  the  man  is  the  prey  of  every  tran- 
sient whim:  he  is,  by  turns,  affectionate  and  cruel,  dar- 
ing and  craven,  buoyed  by  hope  and  crushed  by  despair, 
arrogant  and  full  of  shame,  with  no  sufficient  cause. 
Habitual  excessive  use  of  alcohol  thus  soon  leads  to  a 
state  in  which  the  emotions  are  permanently  overexcited, 
and  the  will  enfeebled.  The  man's  highly  emotional 
state  exposes  him  to  special  temptations,  to  excess  of  all 
kinds  of  passion,  and  his  weakened  will  decreases  his 
power  of  resistance.  The  final  result  is  a  degraded  moral 
condition.  He  who  was  prompt  in  the  performance  of 
duty  begins  to  shirk  that  which  is  irksome;  energy  gives 
place  to  indifference,  truthfulness  to  lying,  integrity  to 
dishonesty,  for  even  with  the  best  intentions  in  making 
promises  or  pledges,  there  is  no  strength  of  will  to  keep 
them  ;  the  man  at  last  becomes  regardless  of  every  duty, 
and  even  unable  to  accomplish  any  which  momentary 
shame  may  make  him  desire  to  perform. 


6.  Point  out  one  of  the  first  effects  of  alcoholic  drinks.  How  il- 
lustrated ?  If  the  amount  is  increased,  what  happens  ?  Illustrate 
from  the  muscles  ?  How  is  the  weakening  of  the  reason  in  a  drunken 
man  exhibited?  To  what  does  habitual  excessive  use  of  alcohol  lead  ? 
What  are  the  consequents  ?  The  final  result?  What  is  the  only 
hope  for  an  habitual  drunkard? 


246  CONFINEMENT  OF  INEBRIATES. 

For  such  a  one  there  is  but  one  hope — confinement  in 
an  asylum  where,  if  not  too  late,  the  diseased  craving 
for  drink  may  be  gradually  overcome,  the  prostrated 
will  regain  its  ascendency,  and  the  man  at  last  gain  the 
victory  over  the  brute. 


GLOSSARY. 


Ab-do'nten(La.t.abdere\  to  conceal,  omentum,  entrails).  The  cavity  containing  the 
stomach,  liver,  intestines,  kidneys,  etc. 

Ab  sorp'tion  (Lat.  absorber e,  to  swallow,  or  take  in).  The  taking  up  of  nutritive 
or  waste  matters  by  the  blood-vessels  or  lymphatics. 

Al-bu'men  (Lat.  from  albus^  white).  The  name  of  a  group  of  nourishing  sub- 
stances containing  nitrogen,  which  resemble  in  nature  the  white  of  an  egg. 

Al-i-ntent'a-ry  (Lat.  alinientarius,  from  alere,  to  nourish).  Pertaining  to  the 
nourishment  of  the  body. 

A-ndt'o-my  (Gr.  anatemnein,  to  cut  up).  The  science  which  deals  with  the  struc- 
ture of  living  things. 

An'eu-rism  (Gr.  aneuristna,  a  widening).  A  swelling  or  tumor  due  to  unhealthy 
dilatation  of  an  artery. 

A-or'ta  (Lat.).     The  great  artery  arising  from  the  left  ventricle  of  the  heart. 

A'gue-ous(Lat.  aqua,  water).     Like  water. 

Ar'ter-y(Gr.  arteria,  the  windpipe).  The  name  given  to  vessels  which  carry 
blood  from  the  heart ;  these  vessels  were  supposed  by  the  old  anatomists  to  con- 
vey only  air,  hence  the  name. 

Ar-tlc'u-lar  (Lat.  articularius).     Pertaining  to  a  joint. 

Ar-tlc-u-la 'tion  (Lat.  articulatio).     The  joining  of  bones  in  the  skeleton. 

A  u'ri-ele  (Lat.  auricula,  a  little  ear).  The  name  given  to  the  chambers  at  the 
base  of  the  heart,  which  receive  blood  from  the  veins,  because  they  have  pro- 
jections which  resemble  in  form  the  ears  of  some  quadrupeds. 

Au'di-to-ry  (Lat.  audire,  to  hear).     Pertaining  to  the  sense  of  hearing. 

Bi'ceps  (Lat.  having  two  heads).     The  name  given  to  muscles  which  split  at  one 

end,  so  as  to  have  there  two  separate  attachments  to  the  skeleton. 
Bi-c&s'pid  (Lat.  bis,  twice,  cuspis,  a  point).     The  name  of  teeth  which  have  two 

points  on  the  crown. 
£rdn'cAz-at(see  Bronchus).    The  name  of  the  branches  of  the  windpipe  inside 

the  lungs. 

Brdn-chi'tis.    Inflammation  of  the  bronchial  tubes  ;  a  cold  "  on  the  chest." 
Brdn'chus  (Gr.  bronchos*  the  windpipe).      The  name  of  the  two  branches  into 

which  the  windpipe  divides  in  order  to  reach  each  lung. 

Ca-nine'  (Lat.  canz'nus,  pertaining  to  dogs).    The  pointed  teeth,  on  each  side  of 

the  incisors,  which  are  very  large  in  dogs. 
C&p'il-la-ry  (Lat.  capillus,  hair).     The  name  given  to  the  smallest  blood-vessels, 

because  they  are  so  slender. 
Car'di-ac  (Gr.  kardia,  the  heart;  also  the  stomach).     The  name  of  the  opening  of 

the  gullet  into  the  stomach;  it  lies  near  the  heart. 
Car'pal  (Gr.  karpos,  the  wrist;.     The  name  given  to  the  wrist-bones. 


248  GLOSSARY. 

Car'ti-lage  (Lat.  cartilagd).  The  technical  name  of  gristle;  an  elastic  flexible  ma- 
terial found  in  the  skeleton. 

Ca'se-ine  (Lat.  caseus,  cheese).  An  albumen  found  in  milk.  When  milk  turns 
sour  the  caseine  curdles,  and  when  the  whey  is  squeezed  out  of  the  curd,  it  re- 
mains as  cheese. 

Cell  (Lat  cella,  a  room  or  cellar).  The  name  of  the  tiny  microscopic  elements 
which,  with  slender  threads  or  fibres,  make  up  most  of  the  body:  they  were  once 
believed  to  be  little  hollow  chambers,  hence  the  name.  Most  animal  cells  are 
not  hollow. 

Cem'-ent.    The  substance  which  forms  the  outer  part  of  the  fang  of  a  tooth. 

Cer-e-bel1  lunt  (Lat.  dim.  ot  cerebrum^  brain).  The  hinder  and  lower  division  of 
the  brain.  The  small  brain. 

Cer'e-bro  spi'nal.     Pertaining  to  the  brain  and  spinal  cord. 

Cer'e-br&m  (Lat.).     The  chief  division  of  the  brain.     The  large  brain. 

Cho'roid  (Gr.  chorion^  a  membrane,  and  eidos,  form).  The  middle  membrane  or 
coat  of  the  eyeball. 

Chyle  (Gr.  chulos,  juice).  The  digested  nutritious  part  of  the  food  prepared  in  and 
absorbed  from  the  intestines. 

Chyme  (Gr.  chumos).  The  name  of  the  partly  digested  food  which  passes  from 
the  stomach  to  the  intestine. 

Cldv'i-cle  (Lat.  clavicula,  a  small  key).  The  collar-bone:  so  named  because  it 
somewhat  resembles  in  form  an  ancient  key. 

Co-dg-ttla'tion  (Lat.  coagulatio).  The  act  of  turning  from  a  liquid  to  a  semi- 
solid  state.  The  clotting  of  blood. 

Coc'fyx  (Gr.  kokkux^  a  cuckoo).  The  lowest  bone  of  the  spinal  column,  named 
from  a  fancied  resemblance  in  form  to  the  bill  of  a  cuckoo. 

Coch'le-a  (Lat.  cochlea,  a  screw).     A  coiled  or  twisted  portion  of  the  internal  ear. 

Con'cha  (Lat.  a  shell).  The  portion  of  the  ear  which  projects  from  the  side  of  the 
head. 

Con-gen* 'tion  (Lat.  congestio,  the  act  of  gathering  into  a  heap).  An  unhealthy  ac- 
cumulation of  blood  in  any  part  of  the  body. 

Con-nect'ive  tissue.  A  tough  stringy  material  used  for  binding  together  the  parts 
of  the  body. 

Con-junc' ti-va  (Lat.  conjunctivus,  serving  to  unite).  The  name  of  the  thin  mem- 
brane which  lines  the  inner  side  of  the  eyelids  and  covers  the  front  of  the  eye- 
balls. 

Con-trac'tion  (Lat.  contract™,  a  drawing  together).  The  shortening  of  muscles 
when  they  work. 

Con-vo-lu'tion  (Lat.  cenvolutus^  twisted  together).  The  winding  ridges  on  the 
surface  of  the  brain. 

Cer'ne-a  (Lat.  corneus^  horny).     The  transparent  membrane  in  front  of  the  eye. 

Cor'pus-cle  (Lat.  corpusculutn^  dim.  of  corpus,  body).  The  name  given  to  the 
minute  particles  which  float  in  the  blood-liquid. 

Cr$s 'tal-llne  (Gr.  krustallinos,  ice-like,  or  resembling  transparent  crystal).  The 
name  of  the  lens  of  the  eye. 

Cu'ti-cle  (Lat.  cuticulus,  dim.  of  cutis,  skin).  The  outer  layer  of  the  skin;  the  epi- 
dermis. 

De-gen-er-a'tion  (Lat.  degenerare,  to  grow'  worse;  to  deteriorate).  A  change  in 
the  structure  of  any  organ  which  makes  it  less  fit  to  perform  its  duty  or  func- 
tion. 

De^-lu-ti'tion  (Lat.  deglutire,  to  swallow  down).  The  actor  process  of  swallowing. 

Den'ttne  (Lat.  dentis,  of  a  tooth).  The  hard  substance  which  forms  most  of  a 
tooth.  Ivory. 


GLOSSARY.  249 

Der'mis  (Gr.  derma,  the  skin  or  hide).  The  deeper  layer  of  the  skin,  containing 
blood-vessels. 

Di'a-phragnt  (Gr.  diaphragnta,  a  partition-wall).  The  muscular  membrane  which 
separates  the  cavity  of  the  chest  ^rom  that  of  the  abdomen. 

Di-ar-rhce'a  (Gr.  diarrein,  to  flow  through)  An  unnaturally  frequent  and  liquid 
evacuation  of  the  bowels. 

Dl-ges'tion  (Lai.  digestio,  the  distribution  of  food  through  the  body).  The  pro- 
cess of  preparing  the  nutritious  parts  of  the  food  for  absorption  from  the  ali- 
mentary canal. 

Dis-lo-ca' tion  (Lat.  dislocare,  to  put  out  of  place).  The  name  of  an  injury  to  a 
joint,  in  which  the  bones  are  forced  out  of  their  sockets. 

Dor'sal  (Lat.  dorsum,  the  back).     Pertaining  to  the  back  of  the  body. 

Dtict  (Lat,  ductus,  a  leading  or  drawing).  A  tube  by  which  fluid  is  conveyed 
from  a  gland. 

Dys-pep'si-a  (Gr.  dus,  ill,  pessein,  to  digest).  A  condition  of  the  alimentary  canal 
in  which  it  digests  imperfectly.  Indigestion. 

En-am' el.    The  smooth  hard  substance  which  covers  that  part  of  a  tooth  which 

projects  beyond  the  gum. 
Ep-i-derm'is  (Gr.  epi,  upon,  derma,  skin).     The  outer   layer  of   the   skin.      The 

cuticle. 
Ep-i-gldt1  tis  (Gr.  epi,  upon,  glotta,  tongue).     A  cartilage  at  the  root  of  the  tongue 

which  closes  the  opening  from  the  throat  to  the  larynx  during  swallowing. 
Ep'i-lep-sy  (Gr.  cpileipsis,  a  failure  or  lack).      A  nervous  disease  accompanied  by 

fits  in  which  consciousness  is  lost.     The  falling  sickness. 
Ea-sta'chi-an  (from  an  Italian  anatomist  named  Eustachi).     The  tube  which  leads 

from  the  throat  to  the  middle  ear  or  tympanum. 
Ex-cre'tion  (Lat.  excretus,  sifted  out).     The  act  of  removing  waste  matters  from 

the  body.     Also  any  such  waste  matter. 
Ex-pi-ra'tion  (Lat.  expiro,  I  emit,  or  breathe  out).     The  act  of  expelling  air  from 

the  lungs. 

Fau'ces  (Lat.}    The  part  of  the  mouth  which  opens  into  the  pharynx. 

Fe'mur  (Lat.)    The  thigh-bone. 

Fl'bre  (Lat.  fibra,  a  filament).    One  of  the  slender  threads  of  which  many  parts  of 

the  body  are  composed. 

Fi 'brine.    The  solid  substance  which  forms  in  blood  when  it  clots. 
Flb'u-la  (Lat.  a  clasp  or  buckle).   The  outer  or  small  bone  of  the  leg,  running  from 

knee  to  ankle. 

F5l'H-cle  (Lat.  folliculus,  a  small  bag).     A  little  cavity  or  pit. 
Fa-ra'men  (Lat.)    A  hole  or  aperture. 
Fiinc'tion  (Lat.  functio,  a  performing  or  executing).     The  special  action  or  duty  of 

any  organ  of  the  body. 
Frdnt'al  (Lat.  frons,  the  forehead).    The  bone  which  supports  the  forehead  and 

closes  the  front  of  the  skull-chamber. 

Gdn'gli-on  (Gr.  a  swelling).     One  of  the  smaller  nerve-centres. 

Gas' trie  (Gr.  gaster,  the  belly).     Belonging  to  the  stomach. 

Gland.    An  organ  which  forms  or  separates  from  the  blood  some  peculiar  liquid, 

either  for  use  in  the  body  (secretion),  or  for  removal  from  it  (excretion). 
Gldt'tis  (Gr.  glotta,  the  tongue).    The  narrow  opening  between  the  vocal  cords. 

Hem'or-rhage  (Gr.  haima,  blood;  regnunai,  to  burst).     Bleeding. 
He-pat' ic  (Gr.  hepatikos).     Pertaining  to  the  liver. 


250  GLOSSARY. 

Ha-me-rus  (Lat.)    The  bone  of  the  arm  between  shoulder  and  elbow. 

Hn'mor  (Lat.  moisture).    The  transparent  liquid  or  semifluid  substances  within 

the  eyeball. 
Hy'gi-ene  (Gr.  Hygeia,  the  goddess  of  health).     That  department  of  knowledge 

which  deals  with  the  preservation  of  health. 
Hy'oid  (Gr.  the  letter  w,  and  eidos,  form).     U-shaped.    The  name  of  the  bone  at 

the  root  of  the  tongue. 

In-ci'sor  (Lat.  incidcre,  to  cut  into).    The  name  of  the  front  teeth. 

In-spi-rd'tion  (Lat.  inspirare,  to  blow  or  breathe  in  or  upon).     The  act  of  drawing 

a  breath. 
In-tes'tlnes  (Lat.  intestinus,  inward).     The  coiled  tube  conveying  food  from  the 

stomach.     The  bowels. 

In-ver'te-brate.     Term  applied  to  animals  having  no  back-bone. 
In-vdl'un-tary  (Lat.  /«,  not;   voluntarius,  acting   on  free    choice).      Performed 

without  direction  from  the  will;  often  against  the  will. 
I'ris  (Lat.  the  rainbow).    The  colored  part  of  the  eye  surrounding  the  pupil. 

Ju'gu-lar  (Lat.  jugulum,  the  hollow  part  of  the  neck  above  the  collar-bone). 
The  name  of  the  chief  veins  of  the  neck. 

Ldb'y-rlnth  (Gr.  labyrinthos,  a  place  full  of  intricate  winding  passages).  The 
name  of  the  inner  portion  of  the  ear. 

Ldch'ry-mal  (Lat.  lacrima,  a  tear).     Pertaining  to  or  conveying  tears. 

Ldc'te-al  (Lat.  lacteus,  milky).  The  name  of  the  lymphatics  or  absorbents  of  the 
small  intestine.  During  digestion  they  are  filled  with  milky-looking  chyle. 

Ldr'ynx  (Gr.)  The  portion  of  the  air-passage,  above  the  windpipe,  in  which 
voice  is  produced. 

Lig'a-ment  {Lat.  ligamentum).  One  of  the  cords  or  bands  used  to  bind  bones 
together  at  joints. 

Lum-bd'go  {Lat.  lumbus,  a  loin).  A  painful  rheumatic  disease  of  the  muscles  of 
the  small  of  the  back. 

Lymph  (Lat.  lympha,  water).  A  colorless  liquid  which  exudes  from  the  blood- 
vessels and  bathes  the  tissues  and  organs. 

Lym-phdt'ic.    The  name  of  the  vessels  which  contain  lymph.    The  absorbents. 

Ma' far  (Lat.  ma/a,  the  cheek).     The  name  of  the  cheek-bone. 

Mdl'le-us  (Lat.  hammer).    The  name  of  the  outermost  bone  within  the  middle  ear. 

Mdm-mdl'i-a  {Lat.  mamma,  a  breast).     The  name  given  to  the  highest  division 

of  back-boned  animals,  because  their  females  suckle  the  young. 
Mds-ti-cd'tion  {Lat.  masticatio).     The  act  of  chewing. 
Max-ll'la  (Lat.  the  jaw).    The  name  of  the  jaw-bones,  upper  and  lower. 
Me-d'tus  (Lat.  a  going  or  course).     A  passage  or  channel,  as  the  external  auditory 

meatus  which  leads  from  the  outer  to  the  middle  part  of  the  ear. 
Me-dHl'la  ob-lon-gd'ta  (Lat.  the  prolonged  or  continued  marrow).     The  continua- 
tion of  the  spinal  cord  {medulla  spinalis)  or  marrow,  which  enters  the  skull. 
Mem'brdne  (Lat.  membrana,  the  thin  skin  covering  the  members  or  limbs).     A 

thin  sheet  of  tissue  used  to  wrap  and  protect  various  organs,  or  to  line  cavities 

in  the  body. 
Mit-a-cdr'pal  (Gr.  meta,  beyond;   karpos,  the  wrist).      The  name  of  the   bones 

between  the  wrist  and  the  fingers. 
MH-a-tar'sal  (Gr.  from   meta.  beyond,  and  tarsal,  which  see).     The  name  of  the 

bones  in  the  front  part  of  the  sole  of  the  foot. 


GLOSSARY.  251 

Mi'tral  (Lat.  ntitra,  a  head-band).  The  name  of  the  valve  between  the  left 
auricle  and  ventricle  of  the  heart,  which  has  two  flaps,  like  the  mitre  of  a 
bishop. 

Mo'lar  (Lat.  mola,  a  well).     The  name  of  the  grinding-teeth. 

Mo' tor  (Lat.  tnovere,  to  move).     Concerned  in  producing  movement. 

Mu'cus  (Lat.  mucus,  the  secretion  of  the  nose).  A  viscid  liquid  secreted  by  cer- 
tain membranes  within  the  body,  named  mucous  membranes. 

Nar-cdt'ic  (Gr.  narkotikos,  from  narke,  numbness).  Any  substance  which  dulls 
the  sensibility  of  the  nerves,  and  in  larger  doses  produces  unnatural  sleep. 

Nd'sal  (Lat.  nasus,  the  nose).  Pertaining  to  the  nose;  the  name  of  the  bones 
which  support  the  bridge  of  the  nose. 

O-d6n'toid(Gr.  odontos,  of  a  tooth;  eidos,  shape).  The  name  of  the  bony  peg  of 
the  second  vertebra,  around  which  the  first  turns. 

(E-sdpk'a-gus  (Gr.  cesophagos).  The  gullet.  The  tube  which  conveys  food  from 
the  throat  to  the  stomach. 

Ol-fdc'to-ry  (Lat.  olfacere,  to  smell).     Pertaining  to  the  sense  of  smell. 

^Op'tic.    Pertaining  or  related  to  the  sense  of  sight. 

Or'gan  (Lat.  organunt,  an  instrument  or  implement).  A  portion  of  the  body  hav- 
ing some  special  function  or  duty. 

Pdl-pi-td'tion  (Lat.  pnlpitatio,  a  frequent  or  throbbing  motion).  A  violent  and 
irregular  beating  of  the  heart. 

Pdn'cre-as  (Gr.pan,a\\\  kreas,  flesh).  One  of  the  most  important  glands  which 
aid  in  the  digestion  of  food.  It  is  placed  in  the  abdomen,  just  below  the  stomach, 
and  pours  its  secretion  into  the  upper  end  of  the  small  intestine. 

Pa-pil'la  (Lat.  a  nipple  or  teat).  The  name  of  the  small  elevations  found  on  the 
skin  and  mucous  membranes. 

Pa-rdl'y-sis  (Gr.  paraluein,  to  set  free  or  separate).  Loss  of  function,  especially 
of  motion  or  feeling.  Palsy. 

Pa-ri'e-tal  (Lat.  paries,  the  wall  of  a  house).  The  name  of  the  bones  on  the  top 
of  the  skull. 

Pa-tel'la  (Lat.).    The  knee-cap  or  knee-pan. 

P&l'vis  (Lat.  a  basin).  The  bony  ring,  made  of  sacrum,  coccyx,  and  the  two  hip- 
bones, which  surrounds  the  lower  part  of  the  abdomen. 

Per-i-cdr' di-unt  (Gr.  peri,  around;  kardia,  the  heart).  The  membranous  sac  which 
encloses  the  heart. 

Per-i-ds' te-um  (Gr.  peri,  around;  esteon,  a  bone).  A  fibrous  membrane  which  sur- 
rounds the  bones. 

Pha-ldn'ges  (Gr.  phalanx,  a  body  of  soldiers  closely  arranged  in  ranks  and  files). 
The  bones  of  the  fingers  and  toes. 

Phdr'ynx  (Gr.  the  throat).  The  cavity  into  which  the  nose  and  mouth  open,  and 
from  which  the  gullet  proceeds. 

Phys-i-ol'o-gy  (Gr.  physis,  nature;  logos,  a  discourse).  The  science  which  treats  of 
the  functions  or  uses  of  the  different  parts  of  animals  and  plants. 

Plds'nta  (Gr.  anything  formed  or  moulded).     The  liquid  part  of  the  blood. 

Pul'mo-na-ry  (Lat.  pulmonis,  of  a  lung).     Pertaining  to  the  lungs. 

Py-lo'rus  (Gr.pyloros,  a  door-keeper).  The  opening  from  the  stomach  into  the 
small  intestine. 

Rd'di-us  (Lat.).    The  outer  of  the  two  bones  running  from  the  elbow  to  the  wrist. 
Re' flex  (Lat.  reflexus,  turned  back).    The  name  given  to  involuntary  movements 

produced  by  an  excitation  travelling  along  a  sensory  to  a  centre,  where  it  is 

turned  back  or  reflected  along  motor  nerves. 


252  GLOSSARY. 

Re'nal(Lat.  rents,  the  kidneys).     Pertaining  to  the  kidneys. 

Ret'in-a  (Lat.  rete,  a  net).  The  transparent  nervous  membrane  which  forms  the 
inner  coat  of  the  eyeball. 

Sd'crum  (Lat.  sacred).     The  large  bone  near  the  lower  end  of  the  spine,  having 

the  hip-bones  attached  to  its  sides. 
Sa-li'va  (Lat.).    The  liquid  which  moistens  the  mouth,  and  aids  in  swallowing  and 

digesting. 
Sa-pke'nous  (Gr.  saphenes,  manifest).     The  name  of  a  large  vein  which  lies  just 

under  the  skin  of  the  leg. 
Scdp'n-la  (Lat.)    The  shoulder-blade. 

Scle-rdt'ic  (Gr.  skier  os,  hard,  tough).    The  tough  outer  coat  of  the  eyeball. 
Se-bd'ceo&s  (Lat.  sebum,  tallow).     The  name  of  the  oil-glands  of  the  skin. 
Se-cre'tion  (Lat.  secretio,  a    separating).     The  preparation    from  the    blood,  by 

glands,  of  peculiar  liquids. 

Sem-l-lu'nar(Lat.  semi,  half;  luna,  mooned).     Shaped  like  a  half-moon. 
Sen-sd'tion  (Lat.  sensus,  feeling).     Any  kind  of  feeling,  as  hunger  or  hearing. 
Se-rum  (Lat.  whey).    The  liquid  part  which  separates  from  the  clot,  when  blood 

coagulates. 
SkeFe-ton  (Gr.  dried  up).     The  bones  and  other  supporting  parts  of  the  body,  as 

gristles  and  connective  tissue. 
Sphe'noid  (Gr.  sphen,  a  wedge;  eidos,  form).    The  name  of  one  of  the  bones  on  the 

under  side  of  the  skull. 
Sta'pes  (Lat.  a  stirrup).    The  name  of  the  innermost  bone  of  the  middle  ear,  which 

has  the  form  of  a  stirrup. 

Ster'num  (Gr.  sternon,  the  chest).     The  breast-bone. 
Stlm'ti-lant  (Lat.  stimulare,  to  goad  or  stir  up).    Any  substance  which  excites 

some  organ  of  the  body  to  do  extra  work,  without  proportionately  nourishing  it. 
Sii-dor-lp' a-ro&s  (Lat.  sudor,  sweat;  parare,  to  prepare).     The  name  of  the  glands 

of  the  skin  which  secrete  sweat  or  perspiration. 
Sut' are  (Lat.  sutura,  a  seam).    The  union  of  certain  bones  of  the  skull  by  the 

interlocking  of  jagged  edges. 
Syn-ov'i-al (Gr.  syn,  with;  oon,  an  egg).    The  liquid  which  lubricates  the  joints. 

joint-oil.    So  called  from  its  resemblance  to  the  white  of  a  raw  egg. 

Tar' sal  (Gr.  tarsos,  a  broad,  flat  surface,  hence  the  sole  of  the  foot).  The  name  of 
the  bones  below  the  ankle-joint. 

Tem'po-ral  (Lat.  tempora,  the  temples).  The  name  of  the  skull-bones  which  sup- 
port the  temples,  and  contain  the  inner  parts  of  the  ear. 

Ten'don  (Lat.  tendere,  to  stretch).     The  cords  which  attach  muscles  to  bones. 

Tho'rax  (Gr.  a  breast-plate).  The  chest.  The  upper  part  of  the  trunk  of  the 
body. 

Tib-i-a  (Lat.)    The  shin-bone. 

Tls'sue  (Lat.  texere,  to  weave).  The  name  given  to  each  of  the  materials  used  in 
the  construction  of  the  body,  as  muscular  tissue,  nervous  tissue,  bony  tissue, 
etc. 

Trd'che-a  (Gr.  trackus,  rough).    The  windpipe. 

Trl-c&s'pid  (Lat.  tris,  three  times;  cuspis,  a  point).  Having  three  points.  The 
name  of  the  valve  between  the  right  auricle  and  ventricle  of  the  heart. 

Tfm'pa-num  (Lat.  a  drum).     The  middle  or  drum  chamber  of  the  ear. 

Ul'na  (Lat.).  One  of  the  two  bones  passing  from  elbow  to  wrist.  It  lies  on  the 
inner  or  little-finger  side. 


GLOSSARY.  253 

U'vu-la  (Lat.  a  little  grape).     The  fleshy  conical  body  which  hangs  down  from  the 
lower  border  of  the  soft  palate. 

Vdr'icdse  (Lat.  varix).    The  term  applied  to  an  unhealthily  distended  vein. 
Vds'cu-lar  (Lat.  vasculum,  a  little  vessel).     Pertaining  to  or  possessing  blood-  or 

lymph-vessels. 

Ven'trAl(L»t.  venter \  the  belly).     Pertaining  to  the  front  or  belly  side  of  the  body. 
Ven'tri-cle  (Lat.  ventriculus.  the  belly).     A  small  cavity,  as  the- ventricles  of  the 

heart.    Also  applied  to  cavities  within  the  brain. 
Ver-te'bra  (Lat.  from  vertere,  to  turn).     The  name  of  each  of  the  bones  of  the 

spinal  column. 
Ves'ti-bale  (Lat.  a  fore-court  or  entry  to  a  house).     A  part  of  the  inner  ear  from 

which  the  other  parts  open. 
Vil'lus  (pi.  vll'll;  Lat.  shaggy  hair).  The  name  of  the  minute  hair-like  projections 

of  the  mucous  membrane  of  the  small  intestine. 
Vlt're-o&s  (Lat.  vitreus,  glassy).     One  of  the  substances  within  the  eyeball,  which 

guide  rays  of  light  to  the  retina. 
Vdl'un-ta-ry  (Lat.  voluntarius).    Applied  to  actions  performed  in  obedience  to  the 

will. 


INDEX. 


ABDOMEN,  6 

Absorbents,  or  lympathic  vessels, 
119 

Absorption,  99;  by  the  lympha- 
tics, 119;  from  the  intestine, 
118;  from  the  stomach,  120 

Air,  how  changed  by  breathing, 
163;  how  purified,  166;  results 
of  breathing  foul,  178 

Air-cells,   171 

Air-passages,  168 

Albumen,  84 

Alcohol,  as  food,  95,  241;  as 
medicine,  97;  as  narcotic,  213, 
216;  as  stimulant,  94;  cause  of 
insanity,  214;  of  premature  old 
age,  244;  of  various  nervous 
diseases,  214;  effects  of,  on 
arteries,  161;  on  the  blood,  161; 
on  character,  245 ;  on  connective 
tissue,  14,  132,  189;  on  diges- 
tive organs,  130;  on  the  heart, 
162;  on  the  joints,  49;  on  the 
kidneys,  189;  on  the  mind,  213; 
on  the  muscles,  58;  on  the 
nervous  system,  212;  on  re- 
spiratory organs,  184;  on  the 
senses,  213,  244;  on  the  skin, 
76;  on  the  temperature  of  the 
body,  96;  on  the  will,  245; 
hereditary  diseases  due  to,  214; 
summary  concerning  the  action 
of  alcohol  on  mind  and  body, 
240 

Alcoholic  stimulants,  94 

Alimentary  canal,  99 

Anatomy,  2,  10 

Aneurism,  162 


Animal  matter,  10;   of  bone,  27; 

starch,  132 
Animal   heat,   76,   82;     influence 

of  alcohol  on,  96 
Anvil-bone,  234 
Aorta,  141 
Apoplexy,  205 
Aqueous  humor,  228 
Arch  of  the  instep,  29 
Arm,  bones  of,   20;    muscles  of, 

40 
Artery,  134;  action  of  alcohol  on, 

161;    pulmonary,    141;  wounds 

of,  159 

Arterial  blood,  134 
Articulations,  35 
Atlas  vertebra,  38 
Attention,  212 
Auditory  organ  (ear),  232;  nerves, 

233 

Auricles,  140 
Axis  vertebra,  38 

BACK-BONE,  5,  16 

Bad  ventilation.  181 

Ball-and-socket  joints,  37 

Bathing,  72 

Beans,  87 

Beat  of  heart,  141 

Beef,  84 

Biceps-muscle  of  arm,  41 

Bicuspid  tooth,  102;  valve,  142 

Bile,  116 

Bladder,  185 

Blister,  60 

Blood,  134,  147;  action  of  alcohol 
on,  161 ;  changed  by  breathing, 
147,  163;  corpuscles  of,  135 


256 


INDEX 


Blood-vessels,  133;  action  of  al- 
cohol on,  161 

Blushing,  63,  153 

Boots,  effects  of  wearing  ill- 
shaped,  30 

Bones,  composition  of,  26;  car- 
pal, 21 ;  fracture  of,  33;  hy- 
giene of,  28;  hyoid,  22;  meta- 
carpal,  21;  metatarsal,  21;  of 
arm,^o;  of  back,  16;  of  fingers, 
21 ;  of  hand,  20;  of  hip,  21;  of 
skull,  19;  of  trunk,  18;  of  wrist, 
21;  structure  of,  24;  tarsal,  21; 
uses  of,  12 

Bony  skeleton,  14;  table  of,  22 

Brain,  195;  controls  the  muscles, 
44;  exercise  of,  208;  feeling 
depends  on,  199,  224;  rest  of, 
207,  210 

Brain  and  mind  connected,  201 

Bread,  84,  87 

Breast-bone,  18 

Breathing,  163;  through  the 
mouth,  183 

Bright's  disease,  189 

Bromides,  220 

Bronchi,  170 

Bronchial  tubes,  170 

Bronchitis,  154 

Burns,  76 

Butter,  86 

CAPILLARIES,  134,  146 

Carbonic  acid,  164 

Carpal  bones,  21 

Cartilage,  12,  13;  in  joints,  36,  37 

Caseine,  86 

Cavity,  abdominal,  6;  dorsal,  5. 

8,  10,  16;  ventral,  5,   10 
Centres,  nervous,  193 
Cerebellum,  194,  199 
Cerebral  hemispheres,  195 
Cerebro-spinal  centre,  194 
Cerebrum,  194,  199,  201 
Cheese,  86 
Chemistry,   of   the   body,    9;    of 

bones,  26    . 
Chest,  6,   expanded   by  exercise, 

183;  injured  by  tight  lacing,  3?, 

182 

Chewing,  108 
Chilblains,  156 


Chloral,  219 

Choroid,  227 

Chyle,  117 

Chyme,  117 

Cigarettes,  222 

Circulation,  133,  143;  effect  of 
muscular  exercise  on,  55,  156; 
hygiene  of,  153;  pulmonary  and 
systemic,  144 

Clavicle,  20 

Cleanliness,  71 

Clothing,  79 

Clotting  of  blood,  138 

Coagulation,  138 

Coccyx,  16 

Cochlea,  235 

Coffee,  93 

Colds,  as  cause  of  digestive  trou- 
bles, 129;  of  kidney-disease, 
188;  of  lung  disease,  154;  how 
to  avoid,  153 

Cold  baths,  72 

Collar-bone,  20 

Complexion,  62 

Concha,  233 

Congestion,  130,  153 

Connective  tissue,  12,  13,  14;  ef- 
fects of  alcohol  on,  14,  132,  189 

Contraction  of  muscles,  35,  39,  41 

Convolutions  of  brain,  195 

Convulsions,  42,  197 

Cooking,  89 

Corn,  87. 

Cornea,  227 

Corpuscles  of  blood,  135 

Cosmetics,  75 

Coughing,  174 

Cranial  nerves,  195 

Crystalline  lens,  228 

Curvature  of  the  spine,  29 

Cuticle,  59 

Cutis,  see  Dermis 

Cuts,  158 

DEAFNESS,  236 

Degeneration,  fatty,  58,162 

Deglutition,  no 

Delirium  tremens,  213 

Demonstration,  on  blood,  148; 
on  circulatory  organs,  149;  on 
digestive  organs,  121;  on  joints, 
47;  on  muscles,  47;  on  renal 


INDEX. 


257 


Demonstration — Continued. 
organs,  189;  on  respiratory  or- 
gans, 175 

Dermis,  59,  63 

Diaphragm,  6,  172 

Diarrhoea,  129 

Diet,  mixed,  127 

Digestion,  98;  in  mouth,  107;  in 
small  intestine,  117;  in  stom- 
ach, 113,  114 

Dipsomania,  214 

Dislocations,  48,  49 

Dorsal  cavity,  5,  8,  10,  16 

Draughts,  effects  of  exposure  to, 
129 

Drum  of  ear,  233 

Duct,  66;  bile,  116;  thoracic,  119 

Dyspepsia,  124 

EAR,  232;  hygiene  of,  235 

Education,  210 

Eggs,  87 

Enamel,  104 

Epidemics,  59 

Epiglottis,  in,  168 

Epilepsy,  205,  214 

Eustachian  tube,  233 

Eye.  225;  hygiene  of,  230 

Eyelids,  231;  secretion  of,  231 

Excretion,  166 

Excretory  organs  compared,  187 

Exercise,    effect    on    the    chest, 

183;  on  the  circulation,  55,  156; 

mental,   208;  muscular,  52 
Expiration,  171 
External  ear,  233 

FAINTING,  204 

Fatty  degeneration,  58,  162 

Fauces,  101 

Feeling,  199,  223 

Femur,  21 

Fever,  67 

Fibres,  14;  of  connective  tissue, 

14;  motor  and  sensory,  196;  of 

nerves,  196 
Fibrin,  138 
Fibula,  21 
Fish,  as  food,  86 
Fits,  204 
Flavors,  238 
Floating  ribs,  18 


Foods,  81,  83;  digested  in  mouth, 
107;  in  small  intestine,  117; 
in  stomach,  113,  114;  proper 
amount  of,  126 

Food-stuffs,  84 

Foramen,  oval,  234 

Foul  air,  178 

Fractures,  33 

Fruits,  87 

Function,  4,  10;  of  back-bone,  17; 
of  blood,  133;  of  blood  vessels, 
134;  of  bones,  13;  of  capilla- 
ries, 147;  of  cartilage,  13,  37; 
of  cerebellum,  199;  of  cere- 
brum, 199,  201;  of  connective 
tissue,  13;  of  contents  of  eye- 
ball, 228;  of  heart,  134;  of  in- 
step, 29;  of  lacteals,  119;  of 
large  intestine,  119;  of  kid- 
neys, 185,  187;  of  liver,  116, 
132;  of  lungs,  171,  187;  of  me- 
dulla oblongata,  198,  199;  of 
muscles,  35,  39,  43;  of  nervous 
system,  190;  of  pancreas,  117; 
of  red  blood-corpuscles,  137;  of 
parts  of  the  ear,  235;  of  sali- 
vary glands,  106;  of  skin,  59, 
187,  236;  of  small  intestine, 
117;  of  stomach,  113;  of  sweat- 
glands,  67,  78;  of  tongue,  105, 
238;  of  valves  of  heart,  142;  of 
valves  of  veins,  156 

Furred  tongue,  105 

GALL,  116 

Ganglia,  201 

Garters,  156 

Gastric  juice,  113 

Gelatin,  27,  88 

Glands,  65;    lachrymal,    231;    of 

eyelids,  231;  of  intestine,  116; 

of  stomach,  113;  salivary,  106; 

sebaceous  or  oil,  66;  sweat  or 

sudoriparous,  66 
Glottis,  169 
Gluten,  87 
Gout,  49 
Gristle,  12,  13 
Growth,  81 
Gullet,  no,  in 

HABITS,  45 


258 


INDEX. 


Hair-dyes,  75 

Hairs,  64 

Hammer-bone,  234 

Hearing,  232 

Heart,  140;  action  of  alcohol  on, 
162;  effect  of  exercise  on,  156 

Health,  why  we  should  try  to 
keep  it,  I  (see  also  Hygiene) 

Heat,  animal,  y£  ,  82 

High-heeled  boots,  30 

Hinge-joints,  37 

Hip-bones,  21 

Hip-joint,  36 

Hollow  veins,  141 

Humerus,  20,  24 

Humors  of  the  eye,  228 

Hygiene,  3;  of  bones,  28;  of  cir- 
culatory organs,  153;  of  diges- 
tive organs,  123;  of  ear,  235; 
of  eye,  230;  of  joints,  48;  of 
kidneys,  188;  of  mind,  208;  of 
muscles,  51;  of  nervous  sys- 
tem, 203;  of  respiration,  176; 
of  skeleton,  28;  of  skin,  71;  of 
teeth,  104 

Hyoid  bone,  22 

Hysterics,  205 

INCUS,  234 
Indigestion,  124 
Inorganic  food-stuffs,  85 
Insanity,  214 
Insomnia,  208 
Inspiration,  171 
Instep,  29 
Internal  ear,  234 
Intestines,   115,   119;   absorption 
from,   118,   119;   digestion    ir, 

H7 

Invertebrate  animals,  8,  n 
Involuntary  muscles,  42 
Iris,  227 
Iron,  as  food,  85 

JELLY,  88 
Joint  oil,  36 

Joints,  35,  36;  demonstration  of, 
47;  hygiene  of,  49;  injuries  of, 

48 


,  185,  187;  action  of  al- 
cohol on,  189;  hygiene  of,  188, 


Knee-pan,  21 

LABYRINTH,  234 

Lachrymal  (or  tear)  glands,  231 

Lacteals,  119 

Large  intestine,  119 

Larynx,  168 

Lean  of  meat,  35 

Ligaments,  14,  37 

Liver,  116,  132;  action  of  alcohol 
on,  131 

Long-sight,  230,  231 

Lumbago,  50 

Lungs,  171,  188;  action  of  alco- 
hol on,  184 

Lymph,  119 

Lymphatics,  or  lymph-vessels,  or 
absorbents,  119 

MAIZE,  87 

Malleus,  234 

Mammalia,  9,  II 

Mammary  glands,  9 

Man  as  a  vertebrate  animal,  8 

Marrow,  of  bone,  24;  spinal,  see 
spinal  cord 

Mastication,  108 

Materials  used  in  building  the 
body,  4,  10 

Meats,  86 

Medulla  oblongata,  195;  func- 
tions of,  198,  199 

Membranes,  14;  mucous,  100; 
tympanic,  233 

Metacarpal  bones,  21 

Metatarsal  bones,  21 

Milk,  86 

Mind  and  brain,  201 

Mineral  matters,  10;  of  bone,  27; 
of  food  (inorganic  food-stuffs), 

85 

Mitral  valve,  142 

Morphia,  218 

Motor  nerve-fibres,  196 

Mouth,  100 

Mouth-breathing,  184 

Movements,  reflex,  197 

Mucous  membrane,  100 

Mucus,  106 

Mumps,  106 

Muscles,  35,  39;  action  of  alco- 
hol on,  58;  contraction  of,.  35, 


INDEX. 


259 


M  uscles — Contin  ued. 

39,  41;  controlled  by  nerves, 
42;  controlled  by  brain,  44; 
demonstration  of,  47 ;  func- 
tions of,  35,  39,  43;  hygiene  of, 
51;  involuntary,  42;  notattach- 
. ed  to  skeleton,  42;  of  standing, 
46;  of  stomach,  114;  parts  of, 
40 

NAILS,  64 

Narcotks,  216 

Nerve-centres,  193 

Nerves,  193:  action  of,  on  mus- 
cles, 42,  197;  cranial  and  spi- 
nal, 195;  of  hearing,  233;  of 
sight,  226;  of  smell,  238;  of 
touch,  236;  structure  of,  196; 
sympathetic,  200 

Nervous  diseases,  204 

Nervous  system,  190,  193;  action 
of  alcohol,  212;  action  of  narco 
tics  on,  216;  injured  by  worry, 
206;  sympathetic,  200 

Neuralgia,  206 

Nitrogen,  85 

ODONTOID  PROCESS,  38 

Odorous  substances,  238 

CEsophagus,  no,  in 

Olfactory  organ.   238 

Oil-glands  of  skin,  67 

Opium,  216 

Optic  nerve.  226 

Organs.  4,  10;  of  circulation,  134; 
of  digestion,  98;  of  excretion, 
187;  of  feeling,  223;  of  hear- 
ing, 232;  of  movement.  35;  of 
respiration,  167;  of  sight,  225; 
of  smell,  238;  of  temperature- 
sense,  237;  of  taste.  238;  of 
touch,  236,  237;  renal,  185,  187 

Osseous  or  bony  skeleton,  14 

Oval  foramen,  234 

Oxidation,  82;  within  the  body, 
165 

PAIN,  223,  236 
Palate,  100 
Pallor,  63 
Pancreas,  117 


Papillae   of  dermis,   63,  237;    of 

tongue,  238 
Paralysis,  199,  214 
Patella,  21 
Peas,  87 
Pelvis,  21 
Pericardium,  140 
Periosteum,  26 
Perspiration,  66 
Phalanges,  21 
Pharynx,  no 
Physiology,  2,  10 
Plasma  of  blood,   137;  action  of 

alcohol  on,  161 
Pivot-joints,  37 
Pork,  89 
Potatoes,  87 
Practical  hints  for  teachers,  47. 

121,  148,  175,  189 
Process,   spinous,   16;    odontoid, 

33 
Pulmonary  artery  and  vein,  141; 

circulation,  144 
Pulse,  145 
Pupil.  227 
Pylorus,  112 

RADIUS,  20,  38 

Rectum,  120 

Reflex  movements,  197 

Renal  organs,  186,  187,  189;  ac- 
tion of  alcohol  on,  189 

Respiration,  163;  hygiene  of,  176 

Respiratory  organs,  167;  action 
of  alcohol  on.  184 

Rest  of  brain,  210;  of  muscles, 
52 

Retina,  227 

Rheumatism    50 

Ribs,  1 8;  movement  in  breath 
ing,  172 

Rice,  87 

SACRUM,  16 
Saliva,  106 
Salt,  85,  86 
Scalds,  76 
Sclerotic,  226 
Scurvy,  88 
Scapula,  20 
Sebaceous  glands,  67 


INDEX. 


Secretion,  66;  of  eyelids,  231;  of 
intestines,  116;  of  kidneys,  185; 
of  liver,  116;  of  pancreas,  117; 
of  skin,  66;  of  stomach,  113 

Semicircular  canals,  235 

Semilunar  valves,  142 

Sensations,  223 

Sense  of  hearing,  232;  of  sight, 
225;  of  smell,  238;  of  tempera- 
ture, 237;  of  touch,  236 

Senses,  223 

Sensory  nerve-fibres,  196 

Serum,  138 

Shin-bone,  21 

Short-sight,  229,  231 

Shoulder  girdle,  20;  blade,  20 

Shower-baths,  74 

Sinews,  40 

Skeleton,  12;  bony,  14;  of  back, 
16;  of  lower  limb,  21;  of  skull, 
19;  of  trunk,  18;  of  upper 
limb,  20;  hygiene  of,  28;  table 
of,  22 

Skin,  59;  action  of  alcohol  on,  76; 
hygiene  of,  71 

Skull,  19 

Sleep,  207 

Small  intestine,  115,116 

Sneezing,  174,  190,  197 

Soap,  74 

Speech,  170 

Spinal  cord,  -95;  functions  of, 
199;  nerves,  195 

Spine,  5.  16 

Spinous  process,  16 

Spleen,  8 

Sprains,  48 

Standing,  44 

Stapes,  234 

Starch,  84,  89;  action  of  saliva  on, 
107;  animal,  132 

Sternum,  18 

Stimulants,  91 

Stirrup-bone.  234 

Stomach,  112;  action  of  alcohol 
on,  130 

St.  Vitus'  dance,  204 

Suffocation,  163,  177 

Sugar,  84;  made  from  starch, 
104;  of  milk,  87 

Sutures,  18 

Swallowing,  no 


I   Sweat-glands,  66,  75 
Sympathetic  nervous  system,  200 
Synovial  liquid,  36 
Systemic  circulation,  144 

TABLE  OF  SKELETON,  22 

Taking  cold,  153 

Tarsal  bones,  21 

Taste,  238 

Tea,  93 

Tears,  231 

Teeth,  101;  hygiene  of,  104 

Temperature  of  the  body,  77 

Tendons,  40 

Thigh-bone,  21 

Thoracic  duct,  119 

Thorax,  6;  injured  by  tight  lac- 
ing, 32 

Tibia,  21 

Tight  lacing,  32,  182 

Tissue,  4,  10;  connective,  12, 13,14 

Tobacco,  221 

Tongue,  105 

Tonsils,  101 

Touch,  236 
j   Trachea,  170 
I   Trichinosis,  89 
'   Tricuspid  valve,  142 

Tympanum,  233 

ULNA,  20,  39 
Upper  limb,  20 
Urea,  185 
Ureter,  185 
Urethra,  187 
Uvula,   101 

VALVES  of  the  heart,  142;  of  veins, 
156 

Varicose  veins,  156 

Veins,  134;  hollow,  161;  pulmo- 
nary, 141;  varicose,  156; 
valves  of,  157;  wounds  of,  159 

Vegetables,  87 

Venae  cavae,  141 

Venous  blood,  134 

Ventilation,  180 

Ventral  cavity,  5,  10 

Ventricles  of  heart,  140 

Vertebra,  16;  atlas,  38;  axis,  38 

Vertebral  column,  16 

Vertebrate  animals,  8,  10 


INDEX. 


26l 


Vestibule,  234 
Villi,  118 

Vitreous  humor,  228 
Vocal  cords,  169 
Voice,  169 

Voluntary  muscles,  42 
Vomer,  22 


WARM  BATHS,  74 
Water,  85 
Whiskey-heart,  162 
Willing,  199 
Windpipe,  6,  170 
Worry,  206 
Wounds,  158 


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